How did some african americans earn their freedom during the antebellum period ?

Free Blacks in the Antebellum Period. Free blacks in the antebellum period--those years from the formation of the Union until the Civil War--were quite outspoken about the injustice of slavery. Their ability to express themselves, however, was determined by whether they lived in the North or the South.

The Underground Railroad had developed as a way in which free blacks and whites (and sometimes slaves) aided fugitive slaves to reach freedom in northern states.