I need evidence that the slaves freed themselves

Underground Railroad.

Explanation:

Slavery was abolished by President Lincoln, but many slaves did free themselves and go north. If they reached the north they were free, so that's what they did. The Underground Railroad wasn't actually a railroad, it was a secret code to a path that went north. One of the post famous "conductors", someone who helped fellow slaves escape to the north, was Harriet Tubman.

i think it should be slowed colonial western march

answer; /// i believe that they became successful farmers; ///////////////