I've been following the threads related to the following question with interest.
Are any volunteers in 1861 recruited for three months, one year or finally three years, as they were historically? This did cause some re-up issues, when terms ran out.
As a side note, the total numbers of soldiers figures, for both sides in the war are somewhat inflated as many men are double counted, or more due to fraudulent bounty signing/deserting/re signing up.