4.)Slavery was defended for many reasons in the 1800s.

A.)Which opinion best explains why some citizens of free states might support slavery?

B.)Slaves were needed to build railroads and new cities in the west.

C.)Escaped slaves should not be protected by the governments of free states.

C.)New states should be able to choose whether slavery would be legal or not.

D.)Southern agriculture was too important for the U.S. economy to lose slave labor.

ANWSER? D?

I agree.

The best opinion that explains why some citizens of free states might support slavery is option D: Southern agriculture was too important for the U.S. economy to lose slave labor.

To arrive at this answer, let's first analyze the given options:

A) Some citizens of free states might support slavery because they believe it to be morally justifiable. While this could be a reason, it is not addressed in any of the given options, so it cannot be the correct answer.

B) Slaves were needed to build railroads and new cities in the west. While this was indeed a reason for supporting slavery, it does not directly align with citizens of free states supporting slavery. Citizens of free states generally refer to people residing in regions where slavery was already abolished, so this option is not the best fit.

C) Escaped slaves should not be protected by the governments of free states. This option refers to protecting escaped slaves, which goes against supporting slavery.

D) Southern agriculture was too important for the U.S. economy to lose slave labor. This option directly addresses the economic importance of slave labor in Southern agriculture, which could have led some citizens of free states to support slavery. This aligns with the question prompt, making it the best answer among the given options.

Therefore, the correct answer is D: Southern agriculture was too important for the U.S. economy to lose slave labor.