This was a depot before becoming a store and filling station. Considering its approximate date of construction, it was likely built by the Macon & Birmingham Railroad or, perhaps, the Southern Railway. I have a couple of books on the Southern Railway, however, and can find no references to a depot at Culloden.
Culloden Historic District, National Register of Historic Places
Culloden is listed as a stop on the Macon and Birmingham timetable in 1906:
https://web.archive.org/web/20061112055602/http://www.railga.com/macbirm06tt.html
Steve Storey’s excellent website on Georgia railroads was taken down a few years ago, I understand because of hacking, but it appears most of it, maybe all of it, can be reached by the web archive link of:
https://web.archive.org/web/20070312105204/http://railga.com/
Sheldon
The Macon and Birmingham Railway (M&B) was a railroad in the southeastern United States that operated from 1891 through 1922. The railroad was chartered on December 26, 1888, by the Macon Construction Company and completed in 1891 before the company went into receivership. In 1902 the line was acquired by the Georgia Southern and Florida Railway, which was affiliated with the Southern Railway. The railroad was abandoned by the GS&F between 1922 and 1923.
With that information, Steve, I’m wondering if it weren’t a depot of the GS&F.