They sometimes grew food for the union army (while the plantation owners were away).
They worked for very little pay and a place to eat and sleep so they were kind of like slaves except indentured servants were treated better.
Signed into law in May 1862, the Homestead Act opened up settlement in the western United States, allowing any American, including freed slaves, to put in a claim for up to 160 free acres of federal land. By the end of the Civil War, 15,000 homestead claims had been established, and more followed in the postwar years.