McLane–Ocampo Treaty

The McLane–Ocampo Treaty, formally the Treaty of Transit and Commerce, was an 1859 agreement negotiated between the United States and Mexico, during Mexico's War of the Reform, when the Veracruz based liberal government of Benito Juárez was fighting against the Mexico City based conservative government.

The treaty granted perpetual transit, military and other extraterritorial rights to the United States and its citizens on Mexican soil and was controversial in both Mexico and the United States. For Mexico, it was seen as a betrayal of the country by ceding sovereignty to the United States, which had already defeated Mexico and annexed vast amounts of its territory in the Mexican–American War a decade before, but it promised the financially strapped liberal government the means to continue the war against conservatives.

Newspapers in Europe and in the United States expressed astonishment at the magnitude of the concessions that had been made and opined that the treaty would turn Mexico into a protectorate of the United States. Ultimately, the U.S. Senate rejected ratification of the treaty in 1860. If it had been ratified, it would have given major control over Mexican territory that was seen as a crucial transit point from the Caribbean to the Pacific Ocean.