Bennett was elected to a number of local positions for the city of Charleston, including Intendant. The prosperous city was a center of trade, including that for slaves. Beginning in 1804, Bennett was elected to the South Carolina House of Representatives for three non-consecutive terms. In 1818, he was elected to the South Carolina Senate. In 1820, the General Assembly elected him as the Governor of South Carolina for the customary two-year term. As governor, Bennett denounced the interstate domestic slave trade. In 1818 the legislature repealed a law that prohibited it.
In mid-June 1822, Charleston white residents were alarmed by reports that a conspiracy had been discovered for a slave rebellion led by free black man Denmark Vesey. The city organized a militia and rapidly arrested a growing circle of suspected conspirators. A Court of Magistrates and Freeholders operated in secret to hear testimony and judge who was guilty. Four household slaves of Bennett were charged as conspirators; three were found guilty and were among five slaves hanged with Vesey on July 2. Bennett was concerned about the way the court was conducting its work and consulted with the state attorney general, Robert Y. Hayne, who advised him that the right of habeas corpus was available only to freemen. In August after the proceedings had ended, Bennett published an article suggesting the insurrection had been exaggerated. He lost the public argument to Intendant James Hamilton, who stressed that white residents had been saved by the city government's quick action. Bennett also submitted a report to the legislature critical of the secret proceedings of the court.
Later life and career
After leaving the governorship in 1822, Bennett returned to Charleston. In about 1825, he constructed a house and lived there; today it is known as the Gov. Thomas Bennett House and listed on the National Register of Historic Places. Later, he was elected to the legislature a final time as a state senator, serving from 1837 to 1840, when he became well known as a Unionist. He died on January 30, 1865 in the last year of the Civil War and was buried at Magnolia Cemetery in Charleston. Bennett is the namesake to the city of Bennettsville, South Carolina.
