Answer: The U.S constitution.
Explanation:provided Congress the power to establish post offices.
The Union blockade of the Southern ports was part of General Scott's Anaconda Plan.
The Anaconda plan involved choking off the Southern supply of goods via a port blockage in tandem with the Union Army coming up, around, and down the Mississippi River and working through the south systemically.
If you mean supreme leader,Dictatorship does for example Kim jong un is a supreme leader and a dictator of North korea