What was the main reason northern states opposed slavery?

Question

Responses
A the "Declaration" forbade itthe "Declaration" forbade it
B slavery wasn't permitted thereslavery wasn't permitted there
C it went against the Constitutionit went against the Constitution
D it was an unfair business advantage

Answer 1

The main reason northern states opposed slavery was largely D: it was an unfair business advantage. While there were multiple factors influencing northern opposition to slavery, including moral and ethical reasons, many in the North believed that slavery provided an unfair economic advantage to southern states, hindering free labor and harming the interests of free workers in the North.