Mike,
As for when Ross was first there, the October 1913 issue of The American Golfer states: "Donald Ross spent a week early in September in Atlanta looking over the new Druid Hills course, which is now about ready for play, and which will be opened early next spring, and the rearranged course of the Atlanta Athletic Club [East Lake]. He has arranged an elaborate system of traps for both these courses, which will be put in during the winter."