In order to attend school, Custer lived with an older half-sister and her husband in Monroe, Michigan. Before entering the United States Military Academy, Custer attended the McNeely Normal School, later known as Hopedale Normal College, in Hopedale, Ohio. It was to train teachers for elementary schools. While attending Hopedale, Custer and classmate William Enos Emery were known to have carried coal to help pay for their room and board. After graduating from McNeely Normal School in 1856, Custer taught school in Cadiz, Ohio. His first sweetheart was Mary Jane Holland.

Custer entered West Point as a cadet on July 1, 1857, as a member of the class of 1862. His class numbered seventy-nine cadets embarking on a five-year course of study. With the outbreak of the American Civil War in 1861, the course was shortened to four years, and Custer and his class graduated on June 24, 1861. He was 34th in a class of 34 graduates: 23 classmates had dropped out for academic reasons while 22 classmates had already resigned to join the Confederacy.

Like the other graduates, Custer was commissioned as a second lieutenant; he was assigned to the 2nd U.S. Cavalry Regiment and tasked with drilling volunteers in Washington, D.C. On July 21, 1861, he was with his regiment at the First Battle of Bull Run during the Manassas Campaign, where Army commander Winfield Scott detailed him to carry messages to Major General Irvin McDowell. After the battle, Custer continued participating in the defenses of Washington D.C. until October, when he became ill. He was absent from his unit until February 1862. In March, he participated with the 2nd Cavalry in the Peninsula Campaign (March to August) in Virginia until April 4.

On April 5, Custer served in the 5th Cavalry Regiment and participated in the Siege of Yorktown, from April 5 to May 4 and was aide to Major General George B. McClellan; McClellan was in command of the Army of the Potomac during the Peninsula Campaign. On May 24, 1862, during the pursuit of Confederate General Joseph E. Johnston up the Peninsula, when General McClellan and his staff were reconnoitering a potential crossing point on the Chickahominy River, they stopped, and Custer overheard Barnard mutter, “I wish I knew how deep it is.” Custer dashed forward on his horse out to the middle of the river, turned to the astonished officers, and shouted triumphantly, “McClellan, that’s how deep it is, General!”

Custer was allowed to lead an attack with four companies of the 4th Michigan Infantry across the Chickahominy River above New Bridge. The attack was successful, resulting in the capture of 50 Confederate soldiers and the seizing of the first Confederate battle flag of the war. McClellan termed it a “very gallant affair” and congratulated Custer personally. In his role as aide-de-camp to McClellan, Custer began his life-long pursuit of publicity. Custer was promoted to the rank of captain on June 5, 1862. On July 17, he was reverted to the rank of first lieutenant. He participated in the Maryland Campaign in September to October, the Battle of South Mountain on September 14, the Battle of Antietam on September 17, and the March to Warrenton, Virginia, in October.

On June 9, 1863, Custer became aide to Brevet Lieutenant Colonel Alfred Pleasonton, who was commanding the Cavalry Corps, Army of the Potomac. Recalling his service under Pleasonton, Custer was quoted as saying that “I do not believe a father could love his son more than General Pleasonton loves me.” Pleasonton’s first assignment was to locate the army of Robert E. Lee, moving north through the Shenandoah Valley in the beginning of what was to become the Gettysburg Campaign.

Pleasonton was promoted on June 22, 1863, to major general of U.S. Volunteers. On June 29, after consulting with his new commander, George Meade, Pleasanton began replacing political generals with “commanders who were prepared to fight, to personally lead mounted attacks”. He found just the kind of aggressive fighters he wanted in three of his aides: Wesley Merritt, Elon J. Farnsworth (both of whom had command experience) and George A. Custer. All received immediate promotions; Custer to brigadier general of volunteers, commanding the Michigan Cavalry Brigade (“Wolverines”). Despite having no direct command experience, Custer became one of the youngest generals in the Union Army at age 23. Custer lost no time in implanting his aggressive character on his brigade, part of the division of Brigadier General Judson Kilpatrick.

On June 30, 1863, Custer and the First and Seventh Michigan Cavalry had just passed through Hanover, Pennsylvania, while the Fifth and Sixth Michigan Cavalry followed about seven miles behind. Hearing gunfire, he turned and started to the sound of the guns. A courier reported that Farnsworth’s Brigade had been attacked by rebel cavalry from side streets in the town. Reassembling his command, he received orders from Kilpatrick to engage the enemy northeast of town near the railway station. Custer deployed his troops and began to advance. After a brief firefight, the rebels withdrew to the northeast. This seemed odd, since it was supposed that Lee and his army were somewhere to the west. Though seemingly of little consequence, this skirmish further delayed Stuart from joining Lee. Further, as Captain James H. Kidd, commander of F troop, Sixth Michigan Cavalry, later wrote: “Under [Custer’s] skillful hand the four regiments were soon welded into a cohesive unit….”

In 1864, with the Cavalry Corps of the Army of the Potomac reorganized under the command of Major General Philip Sheridan, Custer (now commanding the 3rd Division) led his “Wolverines” to the Shenandoah Valley where by the year’s end they defeated the army of Confederate Lieutenant General Jubal Early in the Valley Campaigns of 1864. During May and June, Sheridan and Custer (Captain, 5th Cavalry, May 8 and Brevet Lieutenant Colonel, May 11) took part in cavalry actions supporting the Overland Campaign, including the Battle of the Wilderness (after which Custer ascended to division command), and the Battle of Yellow Tavern (where J.E.B. Stuart was mortally wounded). In the largest all-cavalry engagement of the war, the Battle of Trevilian Station, in which Sheridan sought to destroy the Virginia Central Railroad and the Confederates’ western resupply route, Custer captured Hampton’s divisional train, but was then cut off and suffered heavy losses (including having his division’s trains overrun and his personal baggage captured by the enemy) before being relieved. When Lieutenant General Early was then ordered to move down the Shenandoah Valley and threaten Washington, D.C., Custer’s division was again dispatched under Sheridan. In the Valley Campaigns of 1864, they pursued the Confederates at the Third Battle of Winchester and effectively destroyed Early’s army during Sheridan’s counterattack at Cedar Creek.

On February 9, 1864, Custer married Elizabeth Clift Bacon (1842–1933), whom he had first seen when he was ten years old. He had been socially introduced to her in November 1862, when home in Monroe on leave. She was not initially impressed with him, and her father, Judge Daniel Bacon, disapproved of Custer as a match because he was the son of a blacksmith. It was not until well after Custer had been promoted to the rank of brevet brigadier general that he gained the approval of Judge Bacon. He married Elizabeth Bacon fourteen months after they formally met.

Sheridan and Custer, having defeated Early, returned to the main Union Army lines at the Siege of Petersburg, where they spent the winter. In April 1865 the Confederate lines finally broke, and Robert E. Lee began his retreat to Appomattox Court House, pursued by the Union cavalry. Custer distinguished himself by his actions at Waynesboro, Dinwiddie Court House, and Five Forks. His division blocked Lee’s retreat on its final day and received the first flag of truce from the Confederate force. After a truce was arranged Custer was escorted through the lines to meet Longstreet, who described Custer as having flaxen locks flowing over his shoulders, and Custer said “in the name of General Sheridan I demand the unconditional surrender of this army.” Longstreet replied that he was not in command of the army, but if he was he would not deal with messages from Sheridan. Custer responded it would be a pity to have more blood upon the field to which Longstreet suggested the truce be respected, and then added “General Lee has gone to meet General Grant, and it is for them to determine the future of the armies.” Custer was present at the surrender at Appomattox Court House and the table upon which the surrender was signed was presented to him as a gift for his wife by Sheridan, who included a note to her praising Custer’s gallantry. She treasured the gift of the historical table, which is now in the Smithsonian Institution.

On June 3, 1865, at Sheridan’s behest, Major General Custer accepted command of the 2nd Division of Cavalry, Military Division of the Southwest, to march from Alexandria, Louisiana, to Hempstead, Texas, as part of the Union occupation forces. Custer arrived at Alexandria on June 27 and began assembling his units, which took more than a month to gather and remount. On July 17, he assumed command of the Cavalry Division of the Military Division of the Gulf (on August 5, officially named the 2nd Division of Cavalry of the Military Division of the Gulf), and accompanied by his wife, he led the division (five regiments of veteran Western Theater cavalrymen) to Texas on an arduous 18-day march in August. On October 27, the division departed to Austin. On October 29, Custer moved the division from Hempstead to Austin, arriving on November 4. Major General Custer became Chief of Cavalry of the Department of Texas, from November 13 to February 1, 1866, succeeding Major General Wesley Merritt.

Custer’s division was mustered out beginning in November 1865, replaced by the regulars of the U.S. 6th Cavalry Regiment. Although their occupation of Austin had apparently been pleasant, many veterans harbored deep resentments against Custer, particularly in the 2nd Wisconsin Cavalry, because of his attempts to maintain discipline. Upon its mustering out, several members planned to ambush Custer, but he was warned the night before and the attempt thwarted.

On February 1, 1866, Major General Custer mustered out of the U.S. volunteer service and took an extended leave of absence and awaited orders to September 24. He explored options in New York City, where he considered careers in railroads and mining. Offered a position (and $10,000 in gold) as adjutant general of the army of Benito Juárez of Mexico, who was then in a struggle with the Mexican Emperor Maximilian I (a satellite ruler of French Emperor Napoleon III), Custer applied for a one-year leave of absence from the U.S. Army, which was endorsed by Grant and Secretary of War Stanton. Sheridan and Mrs. Custer disapproved, however, and when his request for leave was opposed by U.S. Secretary of State William H. Seward, who was against having an American officer commanding foreign troops, Custer refused the alternative of resignation from the Army to take the lucrative post.

Following the death of his father-in-law in May 1866, Custer returned to Monroe, Michigan, where he considered running for Congress. He took part in public discussion over the treatment of the American South in the aftermath of the Civil War, advocating a policy of moderation. He was named head of the Soldiers and Sailors Union, regarded as a response to the hyper-partisan Grand Army of the Republic (GAR). Also formed in 1866, it was led by Republican activist John Alexander Logan. In September 1866 Custer accompanied President Andrew Johnson on a journey by train known as the “Swing Around the Circle” to build up public support for Johnson’s policies towards the South. Custer denied a charge by the newspapers that Johnson had promised him a colonel’s commission in return for his support, but Custer had written to Johnson some weeks before seeking such a commission. Custer and his wife stayed with the president during most of the trip. At one point Custer confronted a small group of Ohio men who repeatedly jeered Johnson, saying to them: “I was born two miles and a half from here, but I am ashamed of you.”

On July 28, 1866, Custer was appointed lieutenant colonel of the newly created 7th Cavalry Regiment, which was headquartered at Fort Riley, Kansas. He served on frontier duty at Fort Riley from October 18 to March 26, and scouted in Kansas and Colorado to July 28. 1867. He took part in Major General Winfield Scott Hancock’s expedition against the Cheyenne. On June 26, Lt. Lyman Kidder’s party, made up of ten troopers and one scout, were massacred while en route to Fort Wallace. Lt. Kidder was to deliver dispatches to Custer from General Sherman, but his party was attacked by Lakota Sioux and Cheyenne (see Kidder massacre). Days later, Custer and a search party found the bodies of Kidder’s patrol.

Under Sheridan’s orders, Custer took part in establishing Camp Supply in Indian Territory in early November 1868 as a supply base for the winter campaign. On November 27, 1868, Custer led the 7th Cavalry Regiment in an attack on the Cheyenne encampment of Chief Black Kettle – the Battle of Washita River. Custer reported killing 103 warriors and some women and children; 53 women and children were taken as prisoners. Estimates by the Cheyenne of their casualties were substantially lower (11 warriors plus 19 women and children). Custer had his men shoot most of the 875 Indian ponies they had captured. The Battle of Washita River was regarded as the first substantial U.S. victory in the Southern Plains War, and it helped force a significant portion of the Southern Cheyenne onto a U.S.-assigned reservation.

In November 1868, following the Battle of Washita River, Custer was alleged (by Captain Frederick Benteen, chief of scouts Ben Clark, and Cheyenne oral tradition) to have unofficially married Mo-nah-se-tah, daughter of the Cheyenne chief Little Rock in the winter or early spring of 1868–1869 (Little Rock was killed in the one-day action at Washita on November 27). Mo-nah-se-tah gave birth to a child in January 1869, two months after the Washita battle. Cheyenne oral history tells that she also bore a second child, fathered by Custer in late 1869. Some historians, however, believe that Custer had become sterile after contracting gonorrhea while at West Point and that the father was, in actuality, his brother Thomas. Clarke’s description in his memoirs included the statement, “Custer picked out a fine looking one and had her in his tent every night.”

During the 1920s, two elderly Cheyenne women spoke briefly with oral historians about their having recognized Custer’s body on the battlefield and said that they had stopped a Sioux warrior from desecrating the body. The women were relatives of Mo-nah-se-tah, who was alleged to have been Custer’s lover in late 1868 and through 1869, and borne two children by him. In the Cheyenne culture of the time, such a relationship was considered a marriage. The women allegedly told the warrior: “Stop, he is a relative of ours,” and then shooed him away. The two women said they shoved their sewing awls into his ears to permit Custer’s corpse to “hear better in the afterlife” because he had broken his promise to Stone Forehead never to fight against Native Americans again.

In 1873, Custer was sent to the Dakota Territory to protect a railroad survey party against the Lakota. On August 4, 1873, near the Tongue River, Custer and the 7th Cavalry Regiment clashed for the first time with the Lakota. One man on each side was killed. In 1874 Custer led an expedition into the Black Hills and announced the discovery of gold on French Creek near present-day Custer, South Dakota. Custer’s announcement triggered the Black Hills Gold Rush. Among the towns that immediately grew up was Deadwood, South Dakota, notorious for lawlessness.

Throughout his travels, he gathered geological specimens, sending them to the University of Michigan. On September 10, 1873, he wrote Libbie, “the Indian battles hindered the collecting, while in that immediate region it was unsafe to go far from the command….”

By the time of Custer’s Black Hills expedition in 1874, the level of conflict and tension between the U.S. and many of the Plains Indians tribes (including the Lakota Sioux and the Cheyenne) had become exceedingly high. European-Americans continually broke treaty agreements and advanced further westward, resulting in violence and acts of depredation by both sides. To take possession of the Black Hills (and thus the gold deposits), and to stop Indian attacks, the U.S. decided to corral all remaining free Plains Indians. The Grant government set a deadline of January 31, 1876, for all Lakota and Arapaho wintering in the “unceded territory” to report to their designated agencies (reservations) or be considered “hostile”.

Custer enjoyed writing, often writing all night long. He wrote a series of magazine articles of his experiences on the frontier, which were published book form as My Life on the Plains in 1874. The work is still a valued primary source for information on US-Native relations.

In 1875, the Grant administration attempted to buy the Black Hills region from the Sioux. When the Sioux refused to sell, they were ordered to report to reservations by the end of January, 1876. Mid-winter conditions made it impossible for them to comply. The administration labeled them “hostiles” and tasked the Army with bringing them in. Custer was to command an expedition planned for the spring, part of a three-pronged campaign. While Custer’s expedition marched west from Fort Abraham Lincoln, near present-day Mandan, North Dakota, troops under Colonel John Gibbon were to march east from Fort Ellis, near present-day Bozeman, Montana while a force under General George Crook was to march north from Fort Fetterman, near present-day Douglas, Wyoming.

Custer’s 7th Cavalry was originally scheduled to leave Fort Abraham Lincoln on April 6, 1876, but on March 15 he was summoned to Washington to testify at congressional hearings. Rep. Hiester Clymer’s Committee was investigating alleged corruption involving Secretary of War William W. Belknap (who had resigned March 2), President Grant’s brother Orvil and traders granted monopolies at frontier Army posts. It was alleged that Belknap had been selling these lucrative trading post positions where soldiers were required to make their purchases. Custer himself had experienced first hand the high prices being charged at Fort Lincoln.

At that time the 7th Cavalry’s regimental commander, Colonel Samuel D. Sturgis, was on detached duty as the Superintendent of Mounted Recruiting Service and in command of the Cavalry Depot in St. Louis, Missouri, which left Lieutenant Colonel Custer in command of the regiment. Custer and the 7th Cavalry departed from Fort Abraham Lincoln on May 17, 1876, part of a larger army force planning to round up remaining free Indians. Meanwhile, in the spring and summer of 1876, the Hunkpapa Lakota holy man Sitting Bull had called together the largest ever gathering of Plains Indians at Ash Creek, Montana (later moved to the Little Bighorn River) to discuss what to do about the whites. It was this united encampment of Lakota, Northern Cheyenne, and Arapaho Indians that the 7th met at the Battle of the Little Bighorn in the Crow Indian Reservation created in old Crow Country. (In the Fort Laramie Treaty (1851), the valley of the Little Bighorn is in the heart of the Crow Indian treaty territory and accepted as such by the Lakota, the Cheyenne and the Arapaho). The Lakotas were staying in the valley without consent from the Crow tribe, which sided with the Army to expel the Indian invaders.

President Grant, a highly successful general but recent antagonist, criticized Custer’s actions in the battle of the Little Bighorn. Quoted in the New York Herald on September 2, 1876, Grant said, “I regard Custer’s Massacre as a sacrifice of troops, brought on by Custer himself, that was wholly unnecessary – wholly unnecessary.” General Phillip Sheridan likewise took a harsh view of Custer’s final military actions.

The bodies of Custer and his brother Tom were wrapped in canvas and blankets, then buried in a shallow grave, covered by the basket from a travois held in place by rocks. When soldiers returned a year later, the brothers’ grave had been broken into by animals and the bones scattered. “Not more than a double handful of small bones were picked up.” Custer was reinterred with full military honors at West Point Cemetery on October 10, 1877. The battle site was designated a National Cemetery in 1886.

Several individuals claimed responsibility for killing Custer, including White Bull of the Miniconjous, Rain-in-the-Face, Flat Lip, and Brave Bear. In June 2005, at a public meeting, Northern Cheyenne storytellers said that according to their oral tradition, Buffalo Calf Road Woman, a Northern Cheyenne heroine of the Battle of the Rosebud, struck the final blow against Custer, which knocked him off his horse before he died.