The Sonora Purchase

In 1866, the American government of President William Henry Seward made an offer to the battered Mexico, led by Benito Juárez, to purchase the Baja California peninsula and parts of Sonora and Chihuahua for $15 million. Juárez's government, needing funds desperately, accepted, and this was the new boundary drafted. The Treaty of Washington, which made the purchase official, was ratified by the Senate on May 21, 1866, and by the Mexican National Congress two days after. It transferred nearly six hundred thousand people to U.S. rule.