Top 8 territorial purchases made by the United States

Following the Mexican–American War, Mexico transferred roughly 529,000 square miles of territory under the Treaty of Guadalupe Hidalgo. This treaty of Guadalupe Hidalgo was signed on February 2, 1848, that ended the war between the United States and Mexico. By its terms, Mexico ceded 55 percent of its territory, including the present-day states California, Nevada, Utah, New Mexico, most of Arizona and Colorado, and parts of Oklahoma, Kansas, and Wyoming. Mexico also relinquished all claims to Texas, and recognized the Rio Grande as the southern boundary with the United States.