Born in 1775, he came from Barbados to Florida via Connecticut in 1807 and died in 1839 in St. Augustine, Florida. Col. Dummitt was a planter and officer in the British Marines. His wife was Mary Douglas Mortimer and together they had 11 children of which only 5 children survived. (Douglas D. Dummitt, Elizabeth Hennery Dummitt Hardee, Sara Jane Dummitt Madison, Anna Maria Dummitt, Mortimer Dummitt.)
Col. Thomas Dummitt purchased the plantations of Messrs., Bunch and Addison near the Tomoka River and their 90 slaves where he planned to establish a large sugar plantation and mill. After his house was burned and the plantation destroyed by the Seminole Indians in 1835, he moved his family to St. Augustine and lived in what is now the St. Francis Inn, a Bed and Breakfast. He died in 1839. After his death, his two daughters Sara Jane and Anna Maria and wife Mary operated the home as a boarding house.