The 18th Amendment, prohibiting the importation or sale of liquor, went into effect on January 16, 1920 and the Prohibition Era led to a massive increase in smuggling.

The combined provisions of the 1924 Immigration Act, exempted Mexicans from the quota percentage system, but severely restricted immigrants from South-Western Europe, prompted even more people to try to enter the United States illegally. The US government viewed border security and border protection as a major issue in their attempts to restrict and control immigration into the United States.

US Mexican Border History Facts: Fast Fact Sheet
Fast, fun facts and Frequently Asked Questions (FAQ's) about the US Mexican Border for kids.

How long is the US Mexican Border? The US Mexican Border is 1,989 miles (3,145 km) long, spanning six Mexican states and four U.S. states and stretches from the Gulf of Mexico to the Pacific Ocean.

What are the US states along the Mexican Border? The US states along the Mexican Border are California, Arizona, New Mexico, and Texas.

What are the Mexican Border states? The Mexican Border states are Baja California, Sonora, Chihuahua, Coahuila, Nuevo León, and Tamaulipas

When was the US Mexican Border established?: The US Mexican Border was established by the 1848 Treaty of Guadalupe Hidalgo.

Facts about US-Mexican Border History
The following fact sheet contains interesting facts and information on US-Mexican Border History.

The US Mexican Border was partially established in 1848 by the Treaty of Guadalupe Hidalgo that specified that the middle of Rio Grande was the border.

The 1853 Gadsden Purchase agreed the current boundary line when the US paid  $10 million dollars to extend the southern boundary of New Mexico and Arizona southwards to enable the United States to construct the southern transcontinental railroad.

The International Boundary and Water Commission (IBWC) was created in 1889 by the United States and Mexico to administer the boundary and water rights agreements between the two countries.

In 1902 the Newlands Reclamation Act funded irrigation projects for the arid lands of 20 states in the American West.  Large factory farms sprang up replacing traditional family farms and Mexico provided the greatest source of agricultural labor. Growers increased their profits by employing illegal Mexican labor from across the border.

In 1904 Mounted Guards of the U.S. Immigration Service, operating out of El Paso, Texas,  began patrolling the US Mexican border in an effort to prevent illegal crossings.

In 1910 the Mexican Revolution began and thousands of Mexicans fled across the US border for safety

In 1915 United States Congress authorized "Mounted Inspectors" along the US Mexico Border who operated by horseback, automobiles and on boats..

The United States declared war on Germany on April 6, 1917 and entered into WW1. Intercepting communications to "the enemy" was of greater concern to the government than enforcing immigration regulations.

WW1 created a labor shortage as Americans joined the Allies in Europe and Mexicans were encouraged to work in the USA.

The 18th Amendment, prohibiting the importation or sale of liquor, went into effect on January 16, 1920 and the Prohibition Era led to a massive increase in smuggling across the Mexican border. However, regulations involving customs were extremely difficult to enforce and the bootleggers began smuggling an illegally produced liquor called "Sotol".

The Immigration Act of 1924 restricted the number of immigrants from a given country and prompted even more people to try to enter the United States illegally. The US Mexican Border Patrol became critical to the U.S. Government who passed the 1924 Labor Appropriation Act.

The Labor Appropriation Act of 1924 established the Border Patrol and Border Stations to combat illegal immigration and smuggling. In 1925 the duties were expanded to patrol the seacoast as the government increased their efforts to control the situation

The federal government viewed border security and border protection as a major issue in their attempts to restrict and control immigration into the United States and the Border Patrol expanded to 450 officers.

The government initially provided the Border agents with a revolver and a badge. The Border Patrol began wearing uniforms in 1928.

The first Border Patrol Academy opened in 1934 at Camp Chigas, El Paso. By 1940 there were 1400 agents.

During World War 2 (1939 - 1945), the Patrol provided tighter control of the border and assisted the U.S. Coast Guard in searching for Axis saboteurs. The Bracero Program (1943 - 1965) was established  bringing 5 million temporary Mexican Laborers to work in US farms and on the railroads across a twenty-two year period to help the US economy during, and after, World War Two.

The Immigration and Nationality Act of 1952 expanded the Border Control to include the search of vehicles anywhere in the United States, not just at the point of entry, and illegal immigrants were subject to arrest.

In 1953 "Operation Wetback" was launched as a system of cooperation between the U.S. Border Patrol and the Mexican government to control illegal immigration. During Operation Wetback the U.S. Immigration Service deported more than 3.8 million people of Mexican descent.

In the late 1950's private airplanes were used to carry illegal immigrants from Mexico to America and agents began working with airline industry to combat the trend..

In the early 1960's drug smuggling started to become a significant issue and the Border Patrol began assisting other federal agencies to intercept drugs from Mexico.

In 1964 the first maquiladora factories were established under the Border Industrialization Program

In the 1980's and 1990's the number of illegal immigrants sky-rocketed. The Border Patrol extended their manpower and began to use modern technology to combat the problem.

The Patrol made good use of computer technology and began to use seismic sensors and infrared technology to assist them in border security and protection.

In 1993 the Immigration and Naturalization Service (INS) initiated the "Operation Hold the Line" as a preventative measure against illegal immigration taken by the United States Border Patrol.  "Operation Hold the Line" was initially called "Operation Blockade" and involved a a human and vehicle blockade along the border. There were 400 agents and vehicles every 100 yards from one side of El Paso to the other.

Following the success of "Operation Hold the Line" a new initiative was launched in 1994 called "Operation Gatekeeper" which was located in the San Diego sector.

The Terror Threat: The 9/11 terrorist attacks exposed weaknesses in America's Border systems and Homeland Security became a primary concern. On March 1, 2003 the Department of Homeland Security (DHS) was established, and the US Border Patrol became part of US Customs and Border Protection (CPB).

The Terror Threat: In 2006 the Secure Fence Act authorized fencing along the US-Mexican Border and authorized the use of surveillance technology.

The American states along the Mexican Border are California, Arizona, New Mexico, and Texas.

The Mexican states along the border are Baja California, Sonora, Chihuahua, Coahuila, Nuevo León, and Tamaulipas

There are currently 45 US Mexico border crossings with 330 ports of entry.