Thomas Sandwich b ca 1753 Eng, d 1817 Ga

Thomas Sandwich married Leah Langton Barrett 1776 in London, England. They and their children were in Augusta, Ga by early 1790's. Leah died 1800/1801, Thomas remarried and died 1817 in Augusta. His name was spelled Sambidge and Sambridge on London records. Who were his parents? When and where was he born?