Hartsville, the seat of justice and the county's only town, began in 1797 as Donoho's Mill. Charles and Sarah (Brooks) Donoho and James and Sarah (Hamilton) Hart, and their children, were among the first settlers at this place, the Donohos settlings on the east side of West Fork of Goose Creek and the Harts on the west side on the same stream. The Donohos operated the mill, and nearby on the Cumberland River the Harts opened a ferry in 1798, known for well over a half century as Hart's Ferry. In 1800, Charles Donoho sold his mill to James Hart. Within a few years Hart's Race Track became noted for it's racing. This, the opening of the post office in 1807, and the opening of Andrew Allison and George Black's store put Hartsville on the map indefinitely. In 1817, the State Legislature officially declared Hartsville an established Tennessee town. Damascus, a name given to Donoho's side of the creek, lost currency when both sides of Goose Creek were merged in 1840 under one incorporation by legislative act. James Hart, who died as postmaster and esquire, and on whose land the town was originally laid out, is today known as the Founder of Hartsville, Tennessee.
Wirt Seminary, later known as Wirt College and later still as Enon College, was a rather energetic and well known institution from its beginning in early 1838 until it's final closing in 1881. Its campus was located six miles west of Hartsville near the present Payne's Store. More permanent was the Hartsville Masonic Institute, which also originated about 1838 in the Central Female Academy. The Masonic Order obtained their ownership in 1868, and by September 1875 the Institute had absorbed the nearby Hartsville Masonic Institute Male Academy, established January, 1837. The Hartsville Masonic Institute continued to operate as a private academy with a widespread clientele until 1910 when it became a publicly-owned institution under the name of Hartsville Academy. The old school provided a firm foundation for the present Trousdale County High School which succeeded it in 1916 and which itself occupied the old institute building through December 1919.
The county seat has had its share of fires. Courthouses were lost in the fires of 1900 and 1904. County records were destroyed in 1874, 1900 and 1905, and few records predate 1906. Other fires occurred in 1877 and 1902. Floods have hit every decade or so as well, the most notable being December 1927. Locals refer to such floods as "the back water."
In March of 1883, the telephone reached the old Upper Cumberland of Tennessee and the Hartsville area in particular, and life has never been as "quiet" since, nor events very far away.
The railroad came to Trousdale County in 1892, eventually replacing the river as the major cargo-way and cementing and strengthening the county's position as a major tobacco trade center, for which it has, until recently, been primarily known.
The county's most successful annual event has been the Tobacco Bowl Football Classic, a post-World War II development. Other sports are enjoyed as well.
The county probably has a greater percentage of paved roads than any other county in Tennessee. Trousdale saw its first traffic light go up in 1946, its first parking meters in 1952, its first rest home in 1956, and by 1960 it had six punch-clock-type factories. Between 1880 and 1970, Trousdale's population averaged between five and six thousand, with little variation. The county went Republican for the first time in 1972.
Trousdale County is the smallest county in the state with 75,000 acres.