Answer:
Giving the Union control of the Mississippi River
Explanation:
The Union wanted control of the Mississippi to cut off trade and transport for the South. The river being taken also made things harder for the Confederates (because it cut their side in half, so the Union had the upper hand).
Some would argue the Soviet Union, while others say the US. It depends how you look at the question. There are certain things that prove it was the fault of one while some prove it was the fault of another.
Impressment was a violation of neutral rights
Many Haitians left the country to escape abuses and poor economic conditions.