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, 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. Possibly due to
expanding European settlement in the north, the Cherokee, an Iroquoian
tribe, moved south from the area now called Virginia. As European
colonists spread into the area, and the native populations were forcibly
displaced to the south and west, Muscogee and Chickasaw and Choctaw.
From 1838 to 1839, nearly 17,000 Cherokees were forced to march from
Eastern Tennessee to Indian Territory west of Arkansas. This came to be
known as the Trail of Tears, as an estimated 4,000 Cherokees died along
the way.
Tennessee was admitted to the Union in 1796 as the 16th state, and was
created by taking the north and south borders of North Carolina and
extending them with only one small deviation to the Mississippi River,
Tennessee's western boundary. Tennessee was the last Confederate state
to secede from the Union when it did so on June 8, 1861. After the
American Civil War, Tennessee adopted a new constitution that abolished
slavery (February 22, 1865), ratified the Fourteenth Amendment to the
United States Constitution on July 18, 1866, and was the first state
readmitted to the Union (July 24 of the same year).
The need to create work for the unemployed during the Depression, the
desire for rural electrification, and the desire to control the annual
spring floods on the Tennessee River drove the creation of the Tennessee
Valley Authority, the nation's largest public utility, in 1933.
During World War II, Oak Ridge was selected as a U.S. Department of
Energy national laboratory, one of the principal sites for the Manhattan
Project's production and isolation of weapons-grade fissile material.
