Which issue bitterly divided members of Congress and the people they represented, during the 1800s? A. how to expand the size of the United States
B. whether to make new treaties with Native Americans
C. how to distribute western land to settlers
D. whether to continue to allow slavery

the answer is D

Explanation:whether to continue to allow slavery

crop rotation kepy different plants in the soil instead of once constintly. when switching out plants you have different nutrients being absorbed at different speeds and different roots growing differently therfore the spoil and water flow have to adapt and carry fresh nutrients to carry the constant changes that were going on in the soil.