Blakely Highway, all part of Old GA 363 extends from GA 39 in Blakely to U.S. 84/GA 38 in Saffold near the Alabama border. The former highway is located entirely in southern Early County. While most of it is today C.R. 300, the southermost portion is today part of GA 370.

First commissioned in 1967, GA 363 had shown up on the map years before as a paved county road before being taken over as a state highway. When first designated, GA 363 also originally included one banner route, GA 363 Spur, which extended 3.5 miles from the Cedar Springs community to a railroad track near the Chattahoochee River that is home to the Great Southern Paper Company and Great Southern Plywood Company.

The following year after GA 363 was commissioned, GA 273 was extended west to end at GA 363 Spur. By 1970, GA 363 Spur was eliminated in favor of extending GA 273 west to end at the company. Also in 1970, GA 370 was commissioned and extended to the route, creating a cluster of highways north of Saffold where none previously existed. Although GA 363 was the first to serve that area, it was decommissioned in 1985.

GA 363 in 1969 and 1984. Note how GA 273 ends into GA 363 Spur. GA 273 overtook the spur shortly after it was commissioned, and part of that route is today GA 273 Spur. In the second map, note the addition of GA 370, which ended up taking the place of GA 363 both overall and literally on the south end.