Tennessee is a state located in the Southern United States. In 1796, it became the sixteenth state to join the Union. Tennessee is known as the "Volunteer State," a nickname it earned during the War of 1812, in which volunteer soldiers from Tennessee played a prominent role, especially during the Battle of New Orleans. The capital city is Nashville.

The area now known as Tennessee was first settled by Paleo-Indians nearly 11,000 years ago. The names of the cultural groups that inhabited the area between first settlement and the time of European contact are unknown, but several distinct cultural phases have been named by archaeologists, including Archaic, Woodland, and Mississippian, whose chiefdoms were the cultural predecessors of the Muscogee people who inhabited the Tennessee River Valley prior to Cherokee migration into the river's headwaters.

When Spanish explorers first visited the area, led by Hernando de Soto in 1539–43, it was inhabited by tribes of Muscogee and Yuchi people. Possibly because of European diseases devastating the Native tribes, which would have left a population vacuum, and also from expanding European settlement in the north, the Cherokee moved south from the area now called Virginia. As European colonists spread into the area, the native populations were forcibly displaced to the south and west, including all Muscogee and Yuchi peoples, the Chickasaw, and Choctaw.

Early during the American Revolutionary War, Fort Watauga at Sycamore Shoals (in present day Elizabethton) was attacked in 1776 by Dragging Canoe and his warring faction of Cherokee (also referred to by settlers as the Chickamauga) opposed to the Transylvania Purchase and aligned with the British Loyalists. The lives of many settlers were spared through the warnings of Dragging Canoe's cousin Nancy Ward. The frontier fort on the banks of the Watauga River later served as a 1780 staging area for the Overmountain Men in preparation to trek over the Great Smoky Mountains, to engage, and to later defeat the British Army at the Battle of Kings Mountain in North Carolina.

Eight counties of western North Carolina (and now part of Tennessee) broke off from that state in the late 1780s and formed the abortive State of Franklin. Efforts to obtain admission to the Union failed, and the counties had re-joined North Carolina by 1790. In an effort to encourage settlers to move west into the new territory of Tennessee, in 1787 the mother state of North Carolina ordered a road to be cut to take settlers into the Cumberland Settlements—from the south end of Clinch Mountain (in East Tennessee) to French Lick (Nashville). The Trace was called the "North Carolina Road" or "Avery’s Trace," and sometimes "The Wilderness Road" (not to be confused with Daniel Boone's road through Cumberland Gap).

Tennessee was admitted to the Union in 1796 as the 16th state. The state boundaries, according to the Constitution of the State of Tennessee, Article I, Section 31, stated that the beginning point for identifying the boundary was the extreme height of the Stone Mountain, at the place where the line of Virginia intersects it, and basically ran the extreme heights of mountain chains through the Appalachian Mountains separating North Carolina from Tennessee past the Indian towns of Cowee and Old Chota, thence along the main ridge of the said mountain (Unicoi Mountain) to the southern boundary of the state; all the territory, lands and waters lying west of said line are included in the boundaries and limits of the newly formed state of Tennessee. Part of the provision also stated that the limits and jurisdiction of the state would include future land acquisition, referencing possible land trade with other states, or the acquisition of territory from west of the Mississippi River.

The word Tennessee comes from the Cherokee town Tanasi, which along with its neighbor town Chota was one of the most important Cherokee towns and often referred to as the capital city of the Overhill Cherokee. The meaning of the word "tanasi" is lost (Mooney, 1900). Some believe that Tanasi may mean "River with a big bend," referring to the Cumberland, or that the word Tanasi may have meant "gathering place," as a reference to government or worship for the Native American tribes pre-existent to the pioneer era.

During the administration of U.S. President Martin Van Buren, nearly 17,000 Cherokees were uprooted from their homes between 1838 and 1839 and were forced by the U.S. military to march from "emigration depots" in Eastern Tennessee (such as Fort Cass) toward the more distant Indian Territory west of Arkansas, and during this relocation an estimated 4,000 Cherokees died along the way west. In the Cherokee language, the event is called Nunna daul Isunyi—"the Trail Where We Cried." The Cherokees were not the only Native Americans forced to emigrate as a result of the Indian Removal efforts of the United States, and so the phrase "Trail of Tears" is sometimes used to refer to similar events endured by other Native American peoples, especially among the "Five Civilized Tribes." The phrase originated as a description of the earlier emigration of the Choctaw nation.

Many major battles of the American Civil War were fought in Tennessee—most of them Union victories. It was the last border state to secede from the Union when it joined the Confederate States of America on June 8, 1861. Ulysses S. Grant and the U.S. Navy captured control of the Cumberland and Tennessee rivers in February 1862, and they held off the Confederate counterattack at Shiloh in April. Memphis fell to the Union in June following a naval battle on the Mississippi River in front of the city. Capture of Memphis and Nashville gave the Union control of the western and middle sections; this control was confirmed at the battle of Murfreesboro in early January 1863. But the Confederates held East Tennessee despite the strength of Unionist sentiment there, with the exception of extremely pro-Confederate Sullivan County. The Confederates besieged Chattanooga in early fall 1863, but were driven off by Grant in November. Many of the Confederate defeats can be attributed to the poor strategic vision of General Braxton Bragg, who led the Army of Tennessee from Perryville, KY to Confederate defeat at Chattanooga. The last major battles came when the Confederates invaded in November 1864 and were checked at Franklin, then totally destroyed by George Thomas at Nashville, in December. Meanwhile Andrew Johnson, a civilian, was appointed military governor by President Abraham Lincoln, and slavery was abolished.

After the war, Tennessee adopted a new constitution, which abolished slavery effective February 22, 1865, and also ratified the Fourteenth Amendment to the United States Constitution on July 18, 1866. Andrew Johnson had been elected Vice President with Abraham Lincoln in 1864 and became President after Lincoln's assasination in 1865. Under the lenient re-admission policy of President Johnson, Tennessee was the first seceded state readmitted to the Union, being admitted back into the Union on July 24, 1866. Because it ratified the Fourteenth Amendment, Tennessee was the only state formerly seceded from the Union which did not have a military governor during the Reconstruction period.

In 1897, the state celebrated its centennial of statehood (though one year late of the 1896 anniversary) with a great exposition in Nashville. A full scale replica of the Parthenon was constructed for the celebration, located in what is now Nashville's Centennial Park.

On August 18, 1920, Tennessee became the thirty-sixth and final state necessary to ratify the Nineteenth Amendment to the United States Constitution, which provided women the right to vote.

The need to create work for the unemployed during the Great Depression, a desire for rural electrification, and the need to control annual spring floodings and shipping abilities on the Tennessee River drove the creation of the Tennessee Valley Authority (TVA) in 1933. Tennessee, through the power of TVA, quickly became the nation's largest public utility supplier.

During World War II, the availability of abundant TVA electrical power led the Manhattan Project to locate one of the principal sites for production and isolation of weapons-grade fissile material in East Tennessee. The planned community of Oak Ridge was built from scratch to provide accommodations for the facilities, which are now the sites of Oak Ridge National Laboratory, the Y-12 National Security Complex, and the East Tennessee Technology Park.

Tennessee celebrated its bicentennial in 1996, and with a yearlong statewide celebration entitled "Tennessee 200," opened a new state park (Bicentennial Mall) at the foot of Capitol Hill in Nashville.