 In those formative years, he acted as the first Marion Territorial judge beneath an old oak tree, and as such, he is said to have administered the sworn oath of office to all county officers at the Cotton Gin Port (a Chickasaw Indian trading post located on the east bank of the Tombigbee River), which was then a part of Marion County (now in Mississippi).He also worked as a surveyor of Chickasaw Indian lands in what are now the States of Alabama and Mississippi, as well as served as U.S. Government Chickasaw Indian Agent for that region of the State under Presidents John Quincy Adams and Andrew Jackson.Levi Colbert, head chief of the Chickasaw nation, was one of his most respected friends and had supplied John D. Terrell with his first years supply of corn when he was new to the region.