The chief centers were near Norfolk, where General Butler was the first to establish a "contraband" camp, in North Carolina, and on the Sea Islands of South Carolina, Georgia, and Florida, which had been seized by the Federal fleet early in the war.

To the Sea Islands also were sent, in 1865, the hordes of Negroes who had followed General Sherman out of Georgia and South Carolina.

Through the border states from the Atlantic to the Mississippi and along both sides of the Mississippi from Cairo, Illinois, to New Orleans, there were other refugee camps, farms, and colonies.

For periods varying from one to four years these free Negroes had been at work, often amid conditions highly unfavorable to health, under the supervision of officers of the Treasury Department or of the army.
Emancipation was therefore a gradual process, and most of the Negroes, through their widening experience on the plantations, with the armies, and in the colonies, were better fitted for freedom in 1865 than they had been in 1861.

Even their years of bondage had done something for them, for they knew how to work and they had adopted in part the language, habits, religion, and morals of the whites.