System.Bradford Perkins, The First Rapprochement: England and the United States, 1795–1805 (1955). The Jay Treaty convinced Paris that the United States was no longer a friend. By 1797 the French were openly seizing American ships, leading to an undeclared war known as the Quasi-War of 1798–99. President John Adams tried diplomacy; it failed. In 1798, the French demanded American diplomats pay huge bribes in order to see the French Foreign Minister Talleyrand, which the Americans rejected. The Jeffersonian Republicans, suspicious of Adams, demanded the documentation, which Adams released using X, Y and Z as codes for the names of the French diplomats. The XYZ Affair ignited a wave of nationalist sentiment. Overwhelmed, the U.S. Congress approved Adams' plan to organize the navy. Adams reluctantly signed the Alien and Sedition Acts as a wartime measure. Adams broke with the Hamiltonian wing of his Federalist Party and made peace with France in 1800. 19th century Loss of Saint-Domingue On August 22, 1791, a widespread slave rebellion began the Haitian Revolution, which culminated with the establishment of the independent Empire of Haiti in 1804. Sales of Louisiana to the United States (1803) Napoleon Bonaparte decided not to keep the immense territory of Louisiana that France still possessed. The army he sent to take possession of the colony was first required to put down a revolution in Saint-Domingue (now Haiti); its failure to do so, coupled with the rupture of the Treaty of Amiens with the United Kingdom, prompted him to decide to sell Louisiana to the young United States. This was done on April 30, 1803, for the sum of 80 million francs (15 million dollars). American sovereignty was established on December 20, 1803. Mexico intervention Under Napoleon III, the French led a major expedition to Mexico, in the French intervention in Mexico (January 1862 – March 1867). Napoleon, using as a pretext the Mexican Republic's refusal to pay its foreign debts, planned to establish a French sphere of influence in North America by creating a French-backed monarchy in Mexico, a project that was supported by Mexican conservatives who resented the Mexican Republic's laicism. But his imperial dreams in Mexico would end in failure. The United States was unable to prevent this contravention of the Monroe Doctrine because of the American Civil War; Napoleon hoped that the Confederates would be victorious in that conflict, believing they would accept the new regime in Mexico.