Zemurray’s birth name was Schmuel Zmurri (Yiddish: ‎שמואל ‎זמורי‎, Russian: Шмуэль Давидович Змура, Shmuyel Davidovich Zmura). He was born to a poor Jewish family in Kishinev, Bessarabia, Russian Empire (present-day Chişinău, Moldova). Zemurray grew up on a wheat farm. After his father died, he emigrated to America with his aunt in 1891 at age 14. After landing in New York, he settled in Selma, Alabama, where his uncle owned a general store. Zemurray worked many odd jobs in his youth, being a carpenter’s assistant, delivery boy, traveling merchant, and housecleaner. Eventually, he saved enough money to bring his siblings from Europe to the United States.

Zemurray encountered bananas for the first time in Selma in 1893. At the time, bananas were considered a new and exotic delicacy in the United States, and the industry was growing quickly. Zemurray went to the port of Mobile, Alabama in 1895 to enter the banana trade. Because bananas ripen quickly, the banana trade relied on the ability to quickly bring the produce to market. In Mobile, Zemurray specialized in buying cheap bananas in danger of being overripe and quickly transporting and selling them in the surrounding region by rail. Starting with only $150, he had saved $100,000 by age 21. His success earned him the nickname “Sam the Banana Man”.

In 1903, Zemurray signed a contract with United Fruit, the dominant company in the banana trade. Along with his partner, Ashbell Hubbard, the newly-formed Hubbard-Zemurray Company would buy and distribute United Fruit’s ripest bananas. United Fruit itself bought a portion of Hubbard-Zemurray. In 1905, Zemurray moved to New Orleans and the company acquired Thatcher Brothers Steamship Company. They also acquired the Cuyamel Fruit Company and started using that name for the company. At this time, the company imported bananas from Central American farmers, but did not grow bananas of their own.

Zemurray married Sarah Weinberger in May 1908. Weinberger was the daughter of Jake Weinberger, an early figure in the banana trade and employee of Zemurray’s. Weinberger published a cookbook titled One Hundred Unusual Dinners and How to Prepare Them. Their daughter, archaeologist Doris Zemurray Stone, was born in 1909. Their son, Samuel Jr., was born in 1913. He went missing in action as a pilot in World War II, leaving a widow and two children.

In 1910, Zemurray bought 5,000 acres (20 km²) of land along the Cuyamel River in Honduras, near the town of Omoa. He then continued to borrow money and buy more lowland forest land in Honduras, well-suited for growing bananas. He developed this land by adding plantations, railroads, and bridges. The work was done largely by Jamaican workers, but Zemurray also liked to participate in the physical labor of the fields. At this point, Hubbard believed that Cuyamel Fruit Company’s debts had grown too large, and Zemurray bought his share of the business.

Zemurray had increased the efficiency of his business through bribery and special deals with the Honduran government. But in 1910, the government of Honduras was working to reschedule their sovereign debt owed to the United Kingdom. United States Secretary of State Philander C. Knox facilitated the negotiations, which would place agents of bankers J.P. Morgan and Company in the country’s customs offices to collect the taxes needed to repay the debt. Zemurray feared that the enforcement of these taxes would ruin his business, and he lobbied Knox to make the deal more favorable to him.

Knox made no concessions for Zemurray, and told him not to meddle in Honduran affairs. In spite of this instruction, Zemurray devised a plan to overthrow Honduran president Miguel Dávila in order to prevent the deal. He recruited mercenary Lee Christmas, who in turn recruited a force of about 100 other mercenaries in New Orleans, including famed Jewish soldier Sam Dreben. They sailed to Honduras in a former United States Navy vessel, where they began a war to install exiled Honduran former president Manuel Bonilla, who had been living in New Orleans. Gaining rebel soldiers from the local population, the coup was successful, and Bonilla was inaugurated on February 1, 1912. He then rewarded Zemurray with very favorable tax and land concessions for Cuyamel Fruit Company.

In 1913, Zemurray bought back the portion of his company owned by United Fruit, a transaction that was made possible by increasing anti-trust pressure on United Fruit from the United States government. Fully in control of the company, he expanded by buying 20 ships by 1915 that were outfitted with refrigerated holds. Cuyamel Fruit began to cultivate crops beyond bananas: coconuts, pineapples, palm oil, cattle, lumber, and sugarcane.

During the 1910’s and 1920’s, Zemurray continuously conflicted with United Fruit. Their competition over land in Central America included pranks, sabotage, legal challenges, and approached outright violence. In 1928, a!Q Cuyamel Fruit boat was discovered with a cache of weapons aboard. In 1929, the United States Department of State facilitated discussions between Zemurray and United Fruit to merge their companies and end the conflict, which was endangering American interests abroad. A deal was completed in 1929, in which Zemurray sold Cuyamel to United Fruit for $31.5 million in stock, making him one of the richest people in the United States. Though Zemurray had prided himself on independence, he sold his company because of increasing pressure from the Department of State and because of the financial insecurity brought on by the Great Depression in 1929.

Zemurray retired as president of United Fruit in late 1951. He and his family made generous donations to Tulane University (including a large collection of Mayan artifacts discovered in banana fields), the Zamorano Pan-American Agricultural School, and to other philanthropic ventures, including the Zionist movement through his personal acquaintance, beginning in the 1920s, with Chaim Weizmann. Zemurray supported President Franklin D. Roosevelt’s New Deal policies, helping to draft the Agricultural Adjustment Administration industry codes, and contributed financially to left-wing causes, such as The Nation magazine.

In 1953, the U.S. State Department and United Fruit embarked on a major public relations campaign to convince the American people and the rest of the U.S. government that Colonel Jacobo Arbenz intended to make Guatemala a Soviet “satellite”. Zemurray authorized Edward Bernays to launch a propaganda campaign against Col. Arbenz’s democratically elected government, which intended to expropriate some of the unused land owned by the United Fruit Co. and redistribute it to the local peasants. In 1954, the campaign succeeded and the U.S. Central Intelligence Agency helped orchestrate a coup that replaced Arbenz with a military junta led by Col. Carlos Castillo Armas.