Three Big Things
1. France was mad because the U.S. was making nice with England, who France had only recently helped them break away from and who France hated most of the time anyway.
2. U.S. efforts to make nice with France led to serious drama when French representatives (code names “X,” “Y,” and “Z”) made demands the U.S. contingent found offensive.
3. The resulting kerfuffle led to a “Quasi-War” abroad and more pronounced divisions between political parties at home before being resolved by a new round of diplomacy and a new treaty. The dispute also prompted the Federalists to push through the infamous Alien and Sedition Acts (which didn’t turn out all that well).