The Mexican War of Independence started on September 1810 and ended on September 1821 with the Treaty of Cordoba, which gave Mexican independence from Spain. In addition, the war resulted in Texas becoming part of an independent Mexico. In 1819, the Florida Purchase Treaty gave Florida to the U.S. and set out a boundary between the United States and New Spain (now Mexico). During the war, the United States ceded California, New Mexico, Texas, modern Arizona, Nevada, and Utah to Spain; it also agrees to pay U.S. citizens’ land claims against Spain up to $5 million. The Mexican Republic was established in 1821 when Mexicans won their independence from Spain. Mexico allowed Americans to settle in Texas and gave freedom to travel and trade with Mexico opening, the Santa Fe Trail, that ran 900 miles from Missouri to Santa Fe (now New Mexico). In 1830, Mexico prohibits immigration to Texas from the United States to stem the influx of English-speaking settlers, as Antonio Lopez enforced the law by abolishing slavery and enforcing customs duties. On March 1836, Santa Anna is taken prisoner and signs a treaty recognizing the independence of Texas, and after that in 1845, Texas became part of the United States as a slave state. Mexico then broke the diplomatic relations with the United States.
From 1845 to 1846, President James Polk offers to purchase California and New Mexico from the Mexican government and seeks to make the Rio Grande River the border between the two countries, which would make Texas part of the United States. However, Mexico refused Polk’s offer, and then Polk sent military forces to the Rio Grande in retaliation. In 1848, after the seizure of Mexico City, the Treaty of Guadalupe Hidalgo is signed, ending the Mexican-American War. The treaty obligated Mexico to cede present-day Arizona, California, and New Mexico, and parts of Colorado and Nevada. In return, the United States paid $15 million in compensation for war-related damage to Mexican land. In 1853, U.S. President Franklin Pierce purchased thirty thousand square miles, Gadsden Purchase, of land along the Mesilla Valley for $10 million. Gadsden Purchase resolved the outstanding border dispute between Mexico and the United States. In 1873, the financial Panic in the US called the ‘Long Depression’ led to riots and strikes and an increase in anti-immigrant sentiments. The 1891 Immigration Act was a law that provided for the inspection and deportation of immigrants. In 1907, the restrictive Immigration Act of 1907 was passed and created the Dillingham Commission to review U.S. immigration policy. In 1910, the continued upheaval sent a flood of Mexican immigrants who are seeking refuge to the United States. More than 890,000 Mexicans migrate to the United States between 1910 and 1920, although some of them ultimately return.
In 1915, the US Congress authorized “Mounted Inspectors” along the US-Mexico Border to control the number of immigrants from Mexico, which was claimed to be tripled from 200,000 to 600,000. Between 1921 and 1929, the U.S. Congress passed the Emergency Quota Act of 1921, restricting the flow of Southern and Eastern Europeans into the country. The act established border stations to formally admit Mexican workers and to collect visa fees and taxes from those entering. That same year, 1921, the U.S. Border Patrol is created, but the patrol was primarily focused on the Canadian border. The Great Depression between 1929 and 1939 reversed the flow of immigration from Mexico, as many Mexicans were deported. In 1949, the Border Patrol seized nearly 280,000 illegal immigrants, and by 1953 the numbers of illegal Mexican immigrants seized by the Border Patrol had increased to more than 865,000 Mexicans, which led to the establishment of Operation Wetback.
Operation Wetback was a system of cooperation between the United States Border Patrol and the Mexican government to control illegal immigration. The United States Immigration Service deported more than 3.8 million people of Mexican descent because of Operation Wetback. In September 1969, U.S. President Richard Nixon declares a “war on drugs” and the United States launches an aggressive search-and-seizure counternarcotic operation on the U.S.-Mexico border. In 1986, the United States passes the Immigration Reform and Control Act, which seeks to crack down on undocumented immigration by sanctioning employers who hire unauthorized immigrants. Unauthorized immigration decreases drastically over the next several years, but picks up again at the start of the 1990s. In 1982, the Secure Fence Act authorized fencing and the use of surveillance technology along the US-Mexican Border. Moreover, in February 1994, the United States began a new law enforcement plan that increased border security and pushed for deportation of criminal aliens. Following September 2001, terrorist attacks, the U.S. border security intensifies.
In 2003, the Department of Homeland Security is created, reorganizing the INS as Immigration and Customs Enforcement (ICE). Furthermore, in 2004, Congress authorized hiring an additional ten thousand Border Patrol agent, doubling the force to twenty-one thousand agents by 2010. Mexican migrants who used to return home seasonally now stay in the United States for fear of being apprehended by the Border Patrol. In October 2006, U.S. President Bush signs legislation to build seven hundred miles of fencing along the U.S.-Mexico border.