I cannot find a "Decata" Georgia around Atlanta in the atlases I have. Any chance that this is really "Decatur" which is in DeKalb Cty just east of Atlanta. Dropping the final "r" is quite common in a lot of dialects and it si a short step to start spelling it the way it may be pronounced. There is also a Decatur, Alabama that was the site of a Civil War skirmish in July of 1864.

rich r