Mexican Americans included New Mexican Hispanos and Pueblo Indians and Genizaros, Tejanos, Californios and Mission Indians have existed since the area was part of New Spain. The majority of these historically primarily Hispanophone populations eventually adopted English as their first language as part of their overall Americanization. Approximately ten percent of the current Mexican-American population are descended from the early colonial settlers who became U.S. citizens in 1848 via the Treaty of Guadelupe Hidalgo which ended the Mexican–American War. Although most of the original Mexican American population were officially deemed white citizens by the treaty, they have faced and continue to face
Mexican–American War could not be released from its obligations. The US was released from all obligations of Article XI five years later by Article II of the Gadsden Purchase of 1853. The 1848 Treaty of Guadalupe Hidalgo ended the war and enforced the Mexican Cession of the northern territories of Alta California and Santa Fe de Nuevo México to the United States. Mexico acknowledged the loss of what became the State of Texas and accepted the Rio Grande as its northern border with the U.S. The losses amounted to one-third of its original territory from its 1821 independence. Before the secession of