Morgan returned to North Carolina and purchased 545 acres of land in Anson County, North Carolina, on the Pee Dee River. Morgan Brown III married Elizabeth Clothier on 27 October 1752 in North Carolina, and they had eleven children: Ann Brown (February 13, 1753), Rebeckah Brown (September 14, 1756), Morgan Brown IV (January 13, 1758), Elizabeth Brown (December 11, 1759), Rachel Brown (November 27, 1761), Joseph Brown (November 15, 1763), Edward Brown (February 24, 1767), James C. Brown (January 17, 1770), John W. Brown (February 11, 1772), Jane Brown (March 3, 1774) and Darden Brown (March 23, 1775).
Morgan served as a captain in the Cherokee War of 1759-1760, during which he made two expeditions to Keowee (“the place of the mulberry”), the capital of the Lower Cherokee Indians. Morgan later moved across the border to South Carolina, and settled on Mark’s Creek in Marlboro County, where he built a sawmill and a gristmill. From 1775 to 1777, Morgan served as Overseer of the Road for Anson County, North Carolina. In 1781 and 1782, Morgan Brown III provided sundries for the South Carolina state troops and militia: he supplied 4 bushels of corn for Captain Elholm’s troop of horse, he provided 100 bushels of Indian corn for General Marion’s Brigade, he provided 80 bushels of Indian corn for General Marion’s Brigade, he provided 4 bushels of corn for the drovers under the command of Captain Smith and cattle for General Greene’s Army in South Carolina, and he provided 6 hogs by order of General Marion for the Southern Army. Morgan was paid ₤87, 17 shillings, 1 penny and 3 farthings for providing supplies for the American Army on January 22, 1785. Morgan IV stated that his father was true to the Quaker principles with which he was raised, except he firmly believed in the Revolutionary cause, encouraging his sons to fight for their new country. After ninety years of good health, Morgan passed away on January 28, 1808 in Knoxville, Tennessee.