Someone mentioned in a posting a while back that in the North slave owners were paid $300 for their slaves, when they enlisted, as a bounty.

In Washington DC it was illegal to own slaves after 1850. So if a slave owner, or a Foriegn Diplomat, moved to Washington, the United State would free the slave pay the master $100 and ship the exslave to Liberia, North Africa.

Most of the exslaves in the USCT regiment came from the Contriband camps where finding a means of even staying alive was difficult. The Union Army didn't give those contriband shelter and food for free.

There were roughly 500,000 slaves in state that remained loyal to the Union and 4,000,000 in the Confederacy, not counting free men of color, according to the 1860 census. It is estimated that there were between 180,000 to 200,000 blacks that were enlisted in USCT regiments. By the beginning of 1865 most of the slaves in southern states except southern Virginia, North Carolina and Texas had pretty much been emancipated. By my estimation that is only 4.4% of the Black population joined the USCT regiments. If you double that percentage by halfing the population male and female that still is less than 10% of Black males slaves.

I would assume that the majority of the slaves would have been male to do the labor of the farms. But I am not aware that there has been any detailed studies done in this area. The story of the plite of the Contriband in Union care is not a very pretty one.