Not very. Slavery was originally legal in all the colonies, north and south. When the Civil War ended, there were still slaves in New Jersey, albeit only a small number. See related link below for some excellent information on your question.
Underground railroad, transportation across the border to the North, directions.
Arabs did enslave africans long before the europeans, however the europeans did bring chattell slavery to north America, where it evolved and became the peculiar institution that later begat Jim crow....
most were on the north side because they didnt want slavery
The southern half of the country kept the African-Americans as slaves. The northern states never engaged in that kind of behavior.
When African Americans moved from south to north the great migration.
Slavery
Free African Americans in the North were treated as inferior even after slavery. They had few rights and considered 3/5 human.
The North did not want slavery they thought it was wrong to treat African Americans different from others.
That most Northerners were not fervently anti-slavery.
which was among the rights that free african americans lost in the north and west during the 1820s and 1830s
Because in the second half, it was officially a crusade against slavery.
prejedice and discrimination
To most African Americans the Civil War was a way to become free from slavery. After the Civil War blacks would no longer have to be in slavery, and this is why many African Americans signed up to fight for the Union army. They found this war as an opportunity to have rights, and become a citizen. African Americans fought to show that they did have loyalty to the North.
Free African Americans in the North were treated as inferior even after slavery. They had few rights and considered 3/5 human.
A Lot of them. Now slavery is illegal and now there are no more slaves in north America
The migration of African Americans to the North during and following World War I was mainly a result of the availability of new factory jobs
in the north states