Rev. Walker served as a field chaplin to the Georgia Militia Regiment of Col. Elijah Clarke in the Revolution and continued to serve as a militia chaplin for many years thereafter.

Fishing Creek Baptist Church, the second of this denomination to be constituted in the upcountry of Georgia, was organized in 1782, under the leadership of the Rev. Sanders Walker, who became its first pastor. It was one of five churches represented at a meeting held at Kiokee in October, 1784, to organize the Georgia Baptist Association. In May 1786, the Association met at Fishing Creek. The original church building stood a short distance from this site. He was also a planter and owned many acres in both Wilkes and Ogelthorpe Counties.  Later he founded the County Line Baptist church and is buried at the original site of the church.