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.
They were called A. Anti-Federalists. They thought that the constitution gave too much power to the national government at expense of the state government.
British imperial rule was direct on the american colonies as they were levied heavy taxes by the crown
Explanation:
American colonies were ruled directly by the English crown as the colonies were inflicted with too many taxes. The produce of the colonies were sent to the home land and the profits were also shown to the imperialistic government. As the taxes inflicted were too heavy, people felt the need to secede from the home land and intended to govern themselves.
The declaration of independence is the first document which stated the need of independence and why the Americans decided to secede from the imperialistic rule. Many protests were staged by the annoyed colonists who were repressed by heavy taxes and they were not even given a representation in the parliament.
