Franklin Garrett (September 25, 1906 – March 5, 2000) was the official historian of Atlanta, and wrote the first two volumes of Atlanta and Environs. Those volumes are often a good starting point when researching people and events in Atlanta prior to 1950. He was a fixture on the Atlanta history scene, and I remember in particular his talks at Oakland Cemetery celebrations in the years before his death.
While browsing the Internet Archive I found this video, from a series on railroading called All Aboard, which was at one time hosted by bliptv.com.
The episode is about Atlanta's railroads. It's interesting in its own right, but the most unique feature of the video is a series of segments in which Franklin Garrett talks about the role of the railroads in the founding of Atlanta.