When Birney turned eleven he was sent to Transylvania University in Lexington, Kentucky, where “one of Birney’s teachers, Robert Hamilton Bishop, was one of the state’s earliest outspoken opponents of slavery.” He returned home two years later to enter a school run by a Presbyterian man that had just opened in Danville, where he excelled in his studies, mostly based in the sciences. In 1808, at age seventeen, he entered the College of New Jersey (later, Princeton University). He studied political philosophy, logic, and moral philosophy, and became known as a proficient debater. Among his classmates, he became particularly good friends with George M. Dallas. He studied under the president of the school (Samuel Stanhope Smith), both a logician and an author who was somewhat anti-slavery. He was also exposed to the anti-slavery thinking of John McLean. Birney graduated from Princeton on September 26, 1810.

In May 1814 Birney returned to his hometown and took up the practice of law there, becoming the acting attorney for the local bank. He handled both civil and criminal lawsuits in Danville and other outlying cities of Kentucky. The economy of Kentucky was rather poor at this time, as the War of 1812 had caused a schism in trade within the state. Having trouble making ends meet, Birney made his living at this time primarily as a claims adjuster.

In 1815, he again worked for the successful campaign of Henry Clay, who was running for U.S. Congress. He also campaigned for George Madison, who was running for Kentucky Governor and won (Madison died months later). George Madison was also the maternal uncle of his wife, Agatha McDowell. His political sentiments at the time were with the Democratic-Republican Party. In 1816, Birney won a seat in the Kentucky Legislature representing Mercer County, becoming a member of the Kentucky House of Representatives at age twenty-four. In 1817, the Kentucky Senate drafted a resolution that proposed opening a dialogue between the newly installed governor of Kentucky, Gabriel Slaughter, and the governors of Ohio and Indiana for the purpose of passing laws in those states calling for the capture and return of runaway slaves from Kentucky.

Following in the footsteps of his father, Birney became a freemason upon his return to Danville and a member of Danville’s town council, making him a member of the town’s social elite. He also fell in love with Agatha McDowell and married her on February 1, 1816 at a Presbyterian church; they had 11 children, of whom 6 survived to adulthood. Among the wedding gifts the young couple received were slaves from his father and father-in-law. As Birney had yet to fully develop his abolitionist views, he accepted them kindly. It should be said that later in life Birney was known to say on many occasions that he does not recall ever believing that slavery was right.

In February 1818, he moved his family to Madison County, Alabama, where he purchased a cotton plantation and slaves, most of whom came with him from Kentucky. In 1819, Birney became a member of the Alabama House of Representatives representing Madison County. While there, he helped draft an act that would afford slaves tried by jury paid legal counsel, barring the master and prosecutorial witness or their relatives from being members of the jury. This, along with his opposition to the nomination of Andrew Jackson for U.S. President, hampered many of his future political ambitions in Alabama. He opposed Jackson primarily on the grounds that he was foul-tempered, having executed two men personally.

In 1823, after experiencing many troubles with his cotton plantation, Birney moved to Huntsville, Alabama, to practice law again. His financial troubles were due in part to his habit of horse race gambling, which he gave up eventually after many losses. Most of his slaves stayed on at the plantation, though he did bring with him to Huntsville his servant Michael, as well as Michael’s wife and three children.

At this time there were a number of other practicing lawyers in that area, including one John McKinley. His name preceded him, and he was admitted to the Alabama bar association. McKinley, along with several other prominent members of society, successfully campaigned for Birney to become the Solicitor of Alabama’s Fifth District in 1823. By the end of the year he decided to close his plantation, and sold the slaves at the plantation to a friend of his that was known for his good temperament and kind treatment of slaves. Following the sale of the plantation and slaves, he achieved financial stability, bought a generous plot of land and constructed a large brick house in Huntsville. As was true upon his first return to Danville years back, he once again became a member of the social elite in this new town. In addition to his duties as a public prosecutor, his private law office proved quite lucrative.

By 1825, he was the wealthiest lawyer in northern Alabama, partnering up with Arthur F. Hopkins. The next year, he resigned as solicitor general to pursue his own career with more tenacity. Over the next several years, he worked, often defending blacks, was appointed a trustee of a private school and joined the Presbyterian Church. In 1828, he became an elector on the John Quincy Adams and Richard Rush ticket. He strongly supported Adams for his conservatism, viewing the politics of Andrew Jackson and John C. Calhoun as a threat to the Union. To Birney’s great disappointment, Jackson won. However, he found other ways to champion his beliefs. In 1829, his fellow citizens elected him mayor of Huntsville, Alabama, allowing him to act on his newfound faith and work for reforms in public education and temperance.

Birney’s religious fervor also encouraged him to reevaluate his views on slavery. Increasingly alienated by the politics of the Jackson administration, he discovered the American Colonization Society in 1826. In 1829, he was introduced to Josiah Polk of the ACS by Henry Clay and became an early supporter of the society. He was intrigued by the possibility of solving the supposed problem constituted by free blacks by starting a colony for them in Liberia, Africa. In January 1830 he helped begin a chapter in Huntsville, Alabama, and subscribed to its literature.

In 1831, Birney began considering moving to Illinois, as he was troubled with the idea of his children growing up in a slave state. He mentioned a move to Illinois frequently, stating he would free his remaining slave Michael, Michael’s wife, and three children there. However, this never came to pass. In 1832, the American Colonization Society offered him a position as an agent to travel around the South promoting their cause and he accepted. He met with some success, including organizing the departure of settlers to Liberia and writing essays in defense of colonization. However, in failing to convert his audience to colonization, he began to doubt its effectiveness and the acceptability of slavery. By 1832, he had decided to return to Danville, Kentucky.

A year before returning to Danville, Birney wrote letters to slaveholders in Kentucky who had previously expressed their support for emancipation, suggesting they soon hold a convention on the matter. On December 6, 1832 the gathering was held, with only nine slave owners in attendance. Most of these pledged not to emancipate their current slaves, but to emancipate their slave’s offspring at age twenty-one. This small group also aimed to bring in non-slaveholders to promote this idea of “gradual” emancipation.

In 1833, he read a paper signed by several Christian organizations that repudiated the tenets of the American Colonization Society and, instead, called for the immediate abolition of slavery. Almost the entirety of the following number of the Society’s magazine, African Repository, was devoted to an answer or “review” of him. This, along with life experience and education, brought Birney to the realization that slavery must be abolished once and for all. Inspired by correspondence and discussions with Theodore Weld, the organizer of the Lane Seminary debates, he freed his remaining slaves and declared himself an abolitionist in 1834.

In August 1835, Birney visited Cincinnati to make contacts with friends and fellow members of the abolitionist movement there. He worked to gain support in publishing an anti-slavery newspaper. At this time, there were four newspapers in the city, and all but the Cincinnati Daily Gazette released “critically-roundabout” editorials the next day that assailed the faults of abolitionism in general. One paper, The Daily Post (not to be confused with the Cincinnati Post), even called for lynching those who set out to author anti-slavery literature in their city.

In the Cincinnati Riots of 1836 the press that printed his paper was twice destroyed. However, writing for his newspaper helped him develop ideas for fighting slavery legislatively. He used them as he worked with Salmon P. Chase to protect slaves who escaped to Ohio. In 1837, he was fined $50 (equivalent to $1,130 in 2019) for harboring a slave. That same year, the American Anti-Slavery Society recruited him as an officer and corresponding secretary, and he moved his family to New York.

With the American Anti-Slavery Society’s schism in 1840, he resigned his position as he opposed equal rights for women. Also in that year, the Liberty Party, a newly formed political party whose only aim was abolition, nominated Birney for president. Accurately predicting he would not win, he instead went as a delegate to the World Anti-Slavery Convention in London. The convention named him a vice-president and spread his writings throughout England. When he came back, the Liberty Party made use of his legal expertise in their efforts to defend blacks and fugitive slaves. They chose him as their candidate again in the 1844 presidential election.

In 1841, Birney moved to Saginaw, Michigan, with his new wife and family. He lived at the Webster House in Saginaw for a few months until his home in Bay City, Michigan, was ready. Birney was in the land development business in Bay City. He was a trustee of the reorganized Saginaw Bay Company and was deeply involved in the planning of Bay City, Michigan, where Birney Park is named after him. Birney and the other developers supported churches in their community and set aside money for their construction. In addition to running for the Presidency in 1840 and 1844, Birney received 3023 votes for governor of the State of Michigan in 1845. Birney remained in Michigan until 1855, when his health drove him to move to the East Coast.

In August 1845, Birney suffered from bouts of paralysis following a horseback riding accident, which recurred intermittently for the remainder of his life. His speech became affected as his condition worsened, until he was eventually left to communication through gestures and writing (the latter made difficult by severe tremors). He ended his public career and his direct involvement in the abolitionist movement as a result, though he kept himself informed of new developments. He died in New Jersey in 1857 in a communal settlement surrounded by abolitionist friends Theodore Weld, his wife Angelina Grimké Weld, and her sister Sarah Grimké, convinced that war would be necessary to end slavery. He was buried at the Williamsburg Cemetery in Groveland, New York, the home of his wife’s family. In 1840, he had married Elizabeth Potts Fitzhugh (sister of Henry Fitzhugh and of Ann Carroll Fitzhugh, wife of Gerrit Smith).

In 1889, an all-black school in the Hillsdale neighborhood of Washington, D.C., was named the Birney School in his honor. It later became an elementary school and in 1962 it was renamed Nichols Avenue Elementary School.