Thomas was born in 1843, to John T. Thomas and Jane Ann Remshart. As a child, he had "a delicate constitution and imperfect sight". In 1862, during the
Civil War, he enlisted in Company G (Tattnall Guards), First Volunteer Regiment of Georgia. Due to ill-health, he was assigned to district headquarters and the war tax office. The firm of Purse & Thomas was dissolved in December 1878, and Thomas continued in the coal trade. Thomas made an unsuccessful bid to become
mayor of Savannah in 1889. He formed a partnership, D. R. Thomas & Son, with his son, John Murchison Thomas, in 1892. In 1898, he served again on the city council, during which he was on the special committee to build
Savannah City Hall. He was also a member of Savannah's Sanitary Commission, which studied the city's sewerage and house drainage. He retired from the role in December 1905. The city, in appreciation of his services, named Thomas Park in his honor. He retired from all business in 1910. == Death ==