To make more profit, expand in mercantilism, and gain more raw materials for manufactured goods :)
The law does not require citizens to vote, but voting is a very important part of any democracy. By voting, citizens are participating in the democratic process. Citizens vote for leaders to represent them and their ideas, and the leaders support the citizens' interests.
They wanted to form their own way
The Republican party was the party of the north.
The Democratic party was the party of the south.