Answer: The XYZ Affair was a diplomatic incident between French and United States diplomats that resulted in a limited, undeclared war known as the Quasi-War. U.S. and French negotiators restored peace with the Convention of 1800, also known as the Treaty of Mortefontaine.
The XYZ affair also raised anti-French sentiment which caused the passage of the Alien and Sedition Acts. This was one of the most unpopular pieces of legislation ever passed by Congress. It cost John Adams re-election and allowed Thomas Jefferson to paint him as a monarch
