Why would americans in free states want the slave states to remain part of the united states, as opposed to just letting them leave the union? most northerners recognized the south as part of the united states and felt that the south was crucial to the country's economy. most northerners supported a very strong federal government and believed that only government control could end slavery. most northerners believed the only way to change the slave-holding states was to keep them in the union and work for change through legislative means. most northerners wanted the slave states to remain in the union so that the underground railroad would continue to bring cheap labor to the north. question 2(multiple choice worth 1 points)