I am still new at this, so please be gentle! In reading about Joseph Hooker, I came across this photo titled "Union General Joseph Hooker (seated 2nd to right) and his staff, 1863" on wikipedia. It got me to thinking - how many staff members did a General have? Did it depend on what rank the General was at (Major, Brigadier, etc.), and were all of the staff members officers? And what did they all do?