I did a search about this topic last night and found some posts talking about it, but have yet to be able to determine if the latest patch 1.15 attempted to solve this issue.
I'm playing the Union side in the early 1861 Campaign, and I thought I rather aggressively built up some rather large divisions and armies, only to come to find out that the CSA still has me outnumbered.
So I've gotten to the point as to where I have 1,000+ tons of war supplies, and an ample amount of available cash ($500k+) to spend, but even with both a call for volunteers and a draft, I don't have enough people to build more units!!!
Of course this doesn't make a lot of sense since the Union had an exponential larger pool of population, not to mention supplies and available funds.
Now my Morale has been hovering in the high 80's (guess people didn't like it when I taxed them and called for a draft,) and maybe that is one thing I believe I have read, that if I can get it up to 95 or over maybe I'll have more people to pool from? My Union generals generally lose to CSA generals with armies of equal size and so I've lost a few small battles, but such was the case at least early on in the War.
Any help much appreciated.