Becoming Part of the United States

Spanish-speaking people have lived in North America since the Spaniards established its colonies there in the sixteenth century. By 1800, Spain had governed its lands in North America, including what is now Mexico and many of the southwestern states of the U.S., for hundreds of years. Although Spaniards held positions of power, a large number of the people of this region were mestizos--people of both Spanish and indigenous heritage.

The lands north of the Rio Grande, in what is now the U.S. Southwest, were lightly populated, with government officials, merchants, and trappers and hunters living in small settlements, many centered around mission churches. This arrangement remained largely undisturbed after Mexico won its independence from Spain in 1821.

The Land Changes Hands

In 1846, everything changed. War broke out between the U.S. and Mexico over the U.S. annexation of Texas. Mexico was defeated, and in 1848 the two nations signed the Treaty of Guadalupe Hidalgo. This treaty gave the victorious nation an enormous amount of land, including what would later become the states of California and Texas, as well as parts of Colorado, Arizona, New Mexico, Utah and Nevada, in exchange for a token payment of $15 million.

One more important piece of land changed hands in 1854, when the U.S. bought what is now southern Arizona and New Mexico from the Mexican government for $10 million. This land deal, known as the Gadsden Purchase, brought the U.S. a much-coveted railroad route, and helped open the West to further expansion.

With two strokes of a pen, the larger nation had expanded its size by one-third. And almost overnight, tens of thousands of Mexican citizens had become residents of the United States.