Answer:
The Missouri Compromise of 1820 was a law that tried to address growing sectional tensions over the issue of slavery. By passing the law, which President James Monroe signed, the U.S. Congress admitted Missouri to the Union as a state that allowed slavery, and Maine as a free state
Explanation:
I have no clue of "which of the following" because i cannot see the answers but,
The Great Migration, or the relocation of more than 6 million African Americans from the rural South to the cities of the North, Midwest and West from 1916 to 1970, had a huge impact on urban life in the United States. Driven from their homes by unsatisfactory economic opportunities and harsh segregationist laws, many blacks headed north, where they took advantage of the need for industrial workers that first arose during the First World War. As Chicago, New York and other cities saw their black populations expand exponentially, migrants were forced to deal with poor working conditions and competition for living space, as well as widespread racism and prejudice. During the Great Migration, African Americans began to build a new place for themselves in public life, actively confronting economic, political and social challenges and creating a new black urban culture that would exert enormous influence in the decades to come.
One reason: Plowing large areas of land
A few more reasons: poor farming practices, farmers would loosen up the soil, and the land was deforested, making it loose the roots that held the soil in place.