Why were many northerners opposed to the Mexican American War?

Answer 1

Because the acquisition of new territories would undermine the delicate balance between free and slave territories. This in fact is what happened, eventually becoming the cause of the American Civil War (1861 - 1865)

Answer 2

They worried that new lands would be open for slavery.

Answer 3

They feared the addition of more slave states that would upset the delicate balance created by the compromise of 1850.

Answer 4

They did not want slavery to continue unchecked.

Answer 5

Most opposed slavery and it became a fear that opening new lands to slavery would extend the life of that evil institution.

Answer 6

They were afraid that the war would strengthen the US grip in slavery and ensure southern domination of the union.

Answer 7

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