I started basing the troops from the 250 man project today. Although they need another coat of flat lacquer, here's what I have done so far.
The five Rebel regiments contain 44 bases (132 figures). I have another two regiments' worth of bases already done, so I can field a couple of brigades.
I ran out of bases before I could finish the rest of the Union troops, but I have enough painted troops for over 60 bases.