The correct answer to this open question is the following.
The Founding Fathers created independent institutions like the Supreme Court because it was the best way to maintain a balance of powers in the federal government. The founding fathers established a good system division of powers and checks and balances in which none of the powers of the government could impose its will on the other. So the Executive branch that is the President, the legislative branch that is legislative, and the judicial branch that is the Supreme Court, checks and balances each other to maintain proper balance in the structure of the US government.