GA 187 joined GA 179 as a route originally designated as projected mileage along existing county roads. When this was the case, the route originally ended at GA 94 instead of U.S. 129, as the map on the right shows.

By the early 1950's, the route was moved to its current east-west alignment through Haylow, ending at U.S. 129. The previous route, all in Echols County is today part of Haylow Road (C.R. 121) and unpaved Chauncey Road (C.R. 56).

After GA 187 was relocated, the road alignment was never changed again. However, GA 187 was still entirely unpaved for several more years. In all, it took several years to fully pave the route, but paving was fully completed by the early 1960's.

In the early 1950's, the relocated Echols County section was graded for future paving. In 1954, the route was completely paved except for a large section from the Echols/Clinch County line to a section south of Homerville. Part of GA 187 also remained unpaved in Homerville.

In 1956, the paving was still far from complete, and it appears quite possible that some sections were replaced due to faulty paving. The map that year shows less of the route paved, though the pavement on the south end was extended east (note the east-west section) to the railroad tracks in Clinch County. The northern section paved also appeared shorter on the map, though grading of the road was complete further south.

In 1958, the road was mostly paved, though the remaining unpaved section was graded for completion. By around 1960, the paving was completed. No further changes have been made to the highway since that time.