Was the North truly anti-slavery?

Abolitionism (or the Anti-Slavery Movement) in the United States of America was the movement which sought to end slavery in the United States immediately, active both before and during the American Civil War. In the Americas and western Europe, abolitionism was a movement which sought to end the Atlantic slave trade and set slaves free. In the 17th century, enlightenment thinkers condemned slavery on humanistic grounds and English Quakers and some Evangelical denominations condemned slavery as un-Christian. At that time, most slaves were Africans, but thousands of Native Americans were also enslaved. In the 18th century, as many as six million Africans were transported to the Americas as slaves, at least a third of them on British ships to North America. The colony of Georgia originally prohibited slavery.

In short words:

Abolitionism (or the Anti-Slavery Movement) in the United States of America was the movement which sought to end slavery in the United States.