Mexican immigrants represent approximately one-third of all immigrants living on territory of the United States and more than a half of them are illegal. An illegal immigrant is anybody who has entered a country without government authorization, stayed beyond the expiration date of a visa or has violated the terms of legal entry. Mexicans are one of the oldest inhabitants of the North-American continent because they lived in the southern and western regions of it long before the United States existed as a country. Millions of immigrants living in the United States today refer to themselves either as Mexican immigrants or Mexican Americans. Mexican immigrants are those who emigrate from Mexico to the United States either to settle permanently or to look for seasonal work. Mexican Americans are all those who chose American citizenship after their territories became part of the United States following the defeat of Mexico in the Mexican-American War (1846-48). As a result, Mexican culture and traditions have had a significant impact on the language, food, politics and daily lives of Americans and on the culture and history of the continent as a whole.
The inhabitants of Texas were the first Mexicans to become Mexican Americans without crossing the border. After Mexico declared its independence from Spain in 1821, the newly-formed Mexican government had difficulties with the settling of the province of Texas which was too sparsely populated to sustain itself. Therefore, the government decided to let Anglo-Americans settle there but this soon led to the Texas Revolution against Mexican rule. The Anglo-Texans prevailed and founded their independent Republic of Texas. Later in 1845 the United States officially recognized Texas as a state and annexed it to its territory, while Mexico still considered it part of its territory. The annexation started the Mexican-American War which ended in 1848 with the signing of the Treaty of Guadalupe Hidalgo, under which territorial parts of the defeated country were given to the United States in exchange for 15 million dollars. Those territories later became the states of California and Texas and also included parts of Colorado, Arizona, New Mexico, Utah and Nevada. The remaining southern parts of New Mexico and Arizona were purchased in 1853 for an additional 10 million. Following the Mexican Cession, the inhabitants of these areas had to choose, within one year, between Mexican citizenship and relocation or keeping their residence under U.S. citizenship. Consequently, many Mexicans became American citizens and were promised rights, freedoms and protection of property.
Despite the provisions of the Treaty, Mexican civil and property rights were often violated and disputes in which Mexican landowners and ranchers were deprived of their properties were a common occurrence. In the 1890s many Mexican Americans became victims of land speculators while the newcomers who crossed the U.S. border were a target of pillagers and rustlers. The flow of Mexican immigrants to the United States increased during the gold rush in California in 1849. Mexican miners incorporated their knowledge and skills in mines across California and later in Arizona and New Mexico. Migration flows increased especially during the last years of the Mexican Revolution of the 1910s when many Mexicans sought refuge in the United States from the violence and the lack of reform in their country. With the joining of the United States in World War I (1914-18) in 1917, the U.S. economy experienced labor shortages because workers were sent off to European battlefields. However, the Immigration Act of 1917 was passed which introduced literacy tests and an 8-dollar entrance fee for all immigrants, which significantly decreased legal Mexican immigration because most Mexicans were illiterate and could not afford to pay that amount of money. Yet the U.S. need for cheap labor increased the inflow of illegal Mexican workers who were exploited and often turned in to immigration officials once the job was completed. In order to stop illegal immigration inflow, the United States introduced the Border Patrol in 1924.
During the economic crisis of the Great Depression (1929-41) thousands of Mexican immigrants, both legal and illegal, were deported back to Mexico because their cheap labor was seen as unwanted competition by local workers. However, the need for cheap labor reoccurred during World War II (1939-45) and the United States again turned to Mexico. In turn, Mexico demanded fair treatment of their workers and the bracero program was created. It aimed to protect workers by providing them with contracts in Spanish with a set annual wage along with accommodation and transportation costs.