Although horses remained the transportation of choice for many years, by 1935, the Border Patrol began using motorized vehicles with radios.
Rugged terrain and the need for quick, quiet transportation guaranteed that horses would remain essential transportation to the Patrol even to the present day.
These patrolmen were Immigrant Inspectors, assigned to inspection stations, and could not watch the border at all times.
Military troops along the southwest border performed intermittent border patrolling, but this was secondary to "the more serious work of military training." Aliens encountered illegally in the U. by the military were directed to the immigration inspection stations.
The same year, Border Patrol agents were first permitted to board and search a conveyance for illegal immigrants anywhere in the United States.
For the first time, illegal entrants traveling within the country were subject to arrest.
Agencies charged with inspecting people and goods entering and leaving the U. noticed that their efforts were totally ineffective without border enforcement between inspection stations.
After 1917, a higher head tax and literacy requirement imposed for entry prompted more people to try to enter illegally. Berkshire wrote to the Commissioner-General of Immigration expressing his concerns about the lack of a coordinated, adequate effort to enforce immigration and customs laws along the border with Mexico.
In March 1915, Congress authorized a separate group of Mounted Guards, often referred to as Mounted Inspectors.
Smuggling was commonplace along the Mexican border also.
Whiskey bootleggers avoided the bridges and slipped their forbidden cargo across the Rio Grande by way of pack mules along the Southern border. Roosevelt combined the Bureau of Immigration and the Bureau of Naturalization into the Immigration and Naturalization Service in 1933.
The Eighteenth Amendment to the United States Constitution, prohibiting the importation, transport, manufacture or sale of alcoholic beverages went into effect at midnight on January 16, 1920.
With the passage of this constitutional amendment and the numerical limits placed on immigration to the United States by the Immigration Acts of 19, border enforcement received renewed attention from the government. On May 28, 1924, Congress passed the Labor Appropriation Act of 1924, officially establishing the U. Border Patrol for the purpose of securing the borders between inspection stations.