Formed by the general assembly on December 3, 1807, Rhea County came out of a portion of Roane County. The new county was situated in a valley between the Tennessee River and the Cumberland Plateau. Though enlarged in 1817, parts of the county were lost in the formation of Hamilton County in 1817 and Meigs County in 1836.
Settlers began moving into this valley bottomland once Cherokees gave up claim to it in 1805. Thomas Moore, Joseph Brooks, and John Henry were the original commissioners appointed to select a suitable place for holding court. They decided upon the home of William Henry at Big Spring (north of present-day Dayton); the house served as the county courthouse until October 1812.
In 1809 and in 1811 the general assembly appointed a commission to establish the town of Washington as a county seat. After investigating several sites, Washington (now known as Old Washington) was established in 1812 near the head of Spring Creek on land donated by Judge David Campbell and Richard Green Waterhouse. Lots in the new town were surveyed and sold on May 21 and 22, 1812. Contracts to construct the public buildings were awarded to James C. Mitchell (courthouse), John Moore (jail), and Adam W. Caldwell (stocks and pillory). By 1825 a new jail became a necessity, but it was not completed until 1836. A new brick courthouse, designed by craftsman Thomas Crutchfield, was completed in December 1832.
Washington, the center of political life in Rhea County, was also a thriving marketplace. The town boasted ten stores, three taverns or hotels, a branch of the State Bank, a newspaper (The Valley Freeman), several blacksmiths and cabinetmakers’ shops, a turner (lathe operator), several saddlery and harness shops, a tannery, and three large cotton gins.
During these decades the population of the county began to increase, doubling with each ten-year period–2,504 in 1810 to 4,215 in 1820 to 8,186 in 1830. In 1836 the county’s population declined due to the formation of Meigs County and the founding of Chattanooga a few years later. By 1840 the population had dropped to 3,985, and by 1860 the county had gained only about 1,000 additional residents.
At the beginning of the Civil War, Rhea County had a population of 4,377 whites and 615 slaves. Although 435 men were between the ages of eighteen and forty-five (military age), over 700 men served in the Confederate army and about 100 left the state to join the Union army. Although no large-scale battles took place in Rhea County, the area was constantly under pressure and minor skirmishes were common. Throughout the war troops from both armies crossed the county and the courthouse in Washington was used as a headquarters by various officers in 1863.
During the mid-1880s the Cincinnati Southern Railway was constructed along the west side of the Tennessee River, completely bypassing the county seat of Washington. This lack of a railroad connection led to the decline of Washington; today it is only a small country village.
As Washington dwindled in size, the town of Dayton, known until 1877-78 as Smith’s Cross Roads, rapidly emerged as a major manufacturing center. In 1883-84 English capitalists, recognizing the wealth of coal, iron, and limestone in Rhea County, organized the Dayton Iron and Coal Company, and a town soon began to grow. On March 14, 1885, the residents voted to incorporate the town by a vote of 120 to 13. The first mayor was Thomas N. L. Cunnyngham, and the first recorder was William B. Benson. By 1887 two furnaces were in operation, each turning out approximately one hundred tons of pig iron daily. This company offered employment for a large number of citizens and, along with the railroad, encouraged the growth of Dayton through the turn of the century. In 1889 Rhea Countians voted to move the county seat from Washington to Dayton. The new jail was completed in 1890 and the new brick courthouse, designed by W. Chamberlin & Co. of Knoxville, in 1892.
Sulphur Springs (name changed to Rhea Springs in 1878), situated on the bank of Piney River, was settled early in the county’s existence. This resort area possessed “healing” waters and a large hotel. The railroad bypassed the town, and it dwindled in size. The construction of Watts Bar Dam was the final blow as Rhea Springs was inundated in 1941.
After the demise of Rhea Springs, Spring City, on the Cincinnati Southern Railroad line, emerged as the important town in the northern portion of the county. Unlike most railroad towns, Spring City continued to grow after the 1930s, due mostly to the impact of Watts Bar Dam and, later, the nuclear steam plant.
Other railroad towns were Evensville, Graysville, Roddy (Prestonville), and Pinnine. Settlements away from the railroad included Grandview, Paine Springs, Morgan Springs, Ogdon, Morgantown, Salem, and Carp.
In 1925 Rhea County became internationally famous when the Scopes Trial was held in Dayton. William Jennings Bryan served as prosecutor while Clarence S. Darrow argued for the defense. Dayton teacher John Thomas Scopes was charged with teaching evolution in violation of the Butler Act. The population of Dayton swelled from about 1,800 inhabitants to about 5,000 at the height of the trial. After eight days, Scopes was found guilty and fined one hundred dollars. The 1892 courthouse where the trial took place is still in use and is a National Historic Landmark. Only five days after the end of the trial, Bryan died. William Jennings Bryan College, founded in his honor, was first opened in 1930 and still operates today as Bryan College.
As of 2000, there were 28,400 residents of Rhea County. The TVA’s Watts Bar facility continues to be a major employer as are La-Z-Boy Recliners (2,500 workers), Robinson Manufacturing Company (600 employees), Kayser-Roth Corporation (500 employees), and Suburban Manufacturing Company (380 workers).