Seminole War, in U.S. history, armed conflict between the U.S. government and the Seminoles. In 1832 the U.S. government signed a treaty with the Seminoles, who lived in Florida, providing for their removal to Oklahoma in 1835 in exchange for a small sum of money. However, opposition to the treaty soon appeared among the Seminoles; under the leadership of the young chief, Osceola, the Seminoles organized small raiding parties that attacked the American troops. The U.S. army was rendered helpless by the raiding tactics of the Native Americans and suffered heavy casualties. Although Osceola was captured in 1837 and died in prison a few months later, resistance continued. When Gen. William J. Worth became (1841) commander of U.S. forces, a new strategy was adopted. The Seminole's crops were systematically burned and their villages destroyed. As winter approached and starvation was imminent, the Seminoles surrendered. A peace treaty was signed in 1842 and the Native Americans were removed westward. The war resulted in 1,500 U.S. soldiers killed, and cost more than $20 million.

Seminole, Native North Americans whose language belongs to the Muskogean branch of the Hokan-Siouan linguistic stock (see Native American languages). They separated (their name means "separatist") from the Creek in the early 18th cent. and settled in the former territory of the Apalachee in Florida. They gradually grew in strength, absorbing many runaway black slaves and some members of the Apalachee tribe. While still under Spanish rule, the Seminole became involved in several major confrontations with the United States, particularly in the War of 1812 and again in 1817-18. In the retaliatory expedition of 1817-18, Gen. Andrew Jackson invaded Florida with more than 3,000 men to punish the Seminole. By the Treaty of Paynes Landing (1832), the Seminole were bound to move W of the Mississippi River within three years. Most Seminole, led by Osceola, refused to go and prepared themselves for resistance.

In 1835 began the Seminole War, which proved to be the most costly of the Indian wars in which the United States engaged. Lasting for nearly eight years, it cost the lives of thousands of Seminole and 1,500 U.S. soldiers, as well as at least $30 million. Finally defeated in 1842, the Seminole consented to move to Oklahoma, where they became one of the Five Civilized Tribes. A few Seminole remained isolated in the Everglades. In 1990 there were about 15,500 Seminole in the United States, mostly in Florida and Oklahoma.

North American Indian people living mainly in Florida and Oklahoma, U.S. Their language belongs to the Muskogean language stock. The Seminoles split off from the Creek in the later 18th century and settled in northern Florida, where they were joined by Native American, African, and African American individuals who had escaped slavery in the regions to the north. Their name derives from the Creek word simanó-li, meaning “separatist,” or “runaway.” The Seminoles traditionally lived more by hunting and fishing than by agriculture, constructed shelters of thatched roofs supported by poles, and wore tailored hide clothing decorated with brightly coloured stripes. In an effort to stem colonial encroachment, they fought a succession of wars (see Seminole Wars). Seminole descendants numbered about 27,000 in the early 21st century.

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