Because many first of all disliked Hamilton and many thought his plan only helped the seat he sat in and not the people of the new country
Answer:
The pro-business atmosphere of the 1920s would, however, drain these measures of power. It might be said that the sentiments of the Progressive Era, the idea of helping the weak and taking an active approach to improving society, led to the entry of the United States into World War I (1914–18) in 1917
Explanation:
The 1920s was a decade of the Gregorian calendar that began on January 1, 1920, and ended on December 31, 1929. In North America, it is frequently referred to as the "Roaring Twenties" or the "Jazz Age"
The main reason was the South wanted to preserve slavery. The North wanted to abolish it. If you want some other reasons than slavery, let me know, and I will do my best to add more to this answer.