I believe that I read once that the Confederate Infantry set was in Dragon catalog as a 'coming attraction' but then was never produced.
The 1/32 Italeri sets are scaled-up versions of their 1/72 scale sets. Usable but one piece castings in softer plastic. I think they paint up well but modifications are difficult. The Union Infantry set includes zouaves as well as the more generic uniform. There is no Confederate infantry set but you can paint the Union set as such. Also, there is no Union cavalry set but you can adapt some of the Confederate Cavalry set for Union service. No 1/32 artillery from Italeri.
Same for the A Call to Arms figures-well sculpted, soft plastic one-piece castings, limited number of poses. A Call to Arms has an Iron Brigade set, a USCT (United States Colored Troops) set and a Confederate Infantry set.