The Cyclorama is located in the campus of the Atlanta History Center (AHC). MARTA does not stop too close, about 4 blocks. If you take MARTA's train to the Buckhead station, you can easily (and inexpensively) Uber/Lyft to the AHC. Admission to the Cylorama includes entry into the rest of AHC's museum and campus. I highly recommend taking time to see as much of AHC's Buckhead campus as possible since you will have paid for it and you're already there. The campus is about 30 acres of land and includes the museum, the Smith Tullie farm/farmhouse, the Swan House, AHC gardens and walking trails. There are also 2 restaurants, a coffee shop, gift shop and research center all located on the campus, so you can see why I suggest spending the day. I hope you find this info helpful.
The train does not. But you can take the train to Buckhead Station and board bus 110, which stops pretty close. Bus transfers are free if you've gotten off the train.
Thanks! Your answer is awaiting moderation.