Major Coker was the son of Caleb and Hannah Lide Coker and the great-grandson of Revolutionary War Captains Robert Lide, who moved to South Carolina from Roanoke, Virginia, in 1740, and Thomas Coker, who moved to South Carolina from Brunswick, Virginia, in 1735. Both men fought in Francis Marion's 2nd South Carolina Regiment at Fort Sullivan in 1776 and the Siege of Charleston in 1779, and were awarded tracts of land along the Pee Dee River following the war.