On May 28, 1924, Congress established the Border Patrol as part of the Immigration Bureau in the Department of Labor through the Labor Appropriation Act of 1924.

While initially charged with securing the borders between inspection stations, its patrol areas were expanded in 1925 to include the seacoast along the Gulf of Mexico and Florida. In 1932, supervision of the Border Patrol was divided under two directors: one in charge of the Mexican border, the other in charge of the Canadian border.
The Border Patrol was first permitted to board and search a conveyance for illegal aliens in 1952. Agents also were allowed to patrol all territory within 25 miles of a land border.
At the dissolution of INS in 2003, the Border Patrol became part of CBP.
Expanded History:
In the nineteenth century, United States borders were open and unrestricted; there was no systematic control or even record-keeping of immigrants. The first legislation restricting immigration, after the Act Prohibiting Importation of Slaves of 1807, was the Chinese Exclusion Act of 1882.
Mounted watchmen of the United States Department of Commerce and Labor patrolled the border in an effort to prevent illegal crossings as early as 1904, but their efforts were irregular and undertaken only when resources permitted. The inspectors, usually called "mounted guards", operated out of El Paso, Texas. Though they never totaled more than 75, they patrolled as far west as California trying to restrict the flow of illegal Chinese immigration.
In March 1915, Congress authorized a separate group of mounted guards, often referred to as "mounted inspectors". Most rode on horseback, but a few operated automobiles, motorcycles, and boats. Although these inspectors had broader arrest authority, they still largely pursued Chinese aliens trying to avoid the National Origins Act and Chinese Exclusion Act of 1882. These patrolmen were immigration inspectors, assigned to inspection stations, and could not watch the border at all times. U.S. Army soldiers 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.S. by the Army were directed to the immigration inspection stations. Texas Rangers were also sporadically assigned to patrol duties by the state, and their efforts were noted as "singularly effective".
The National Origins Act authorized the formation of the U.S. Border Patrol on May 26, 1924. Two days later, the Labor Appropriation Act of 1924 established the Border Patrol as an agency of the U.S. Department of Labor assigned to prevent illegal entries, primarily along the Mexico–United States border, as well as the Canada–U.S. border. The first Border Patrol station began operations in Detroit, Michigan, in June 1924. A second station, in El Paso, Texas, began operations in July 1924. In 1925, coastal patrols began as well. Operations were established along the Gulf Coast in 1927 to ensure that foreign crewmen departed on the same ship on which they arrived. In 1932, the Border Patrol was divided into two offices. Mexican border operations were directed from El Paso, Texas, and Canadian border operations were directed from Detroit, Michigan. The Canadian border operations from Detroit employed more men than the El Paso operations along the Mexican border because of a focus on the prevention of liquor smuggling during prohibition. Franklin Delano Roosevelt's Executive Order 6166 formed the Immigration and Naturalization Service (INS) in 1933 by consolidation of the Bureau of Immigration and the Bureau of Naturalization. Following the outbreak of World War II in Europe, Border Patrol staffing doubled to 1,500 in 1940, and the INS was moved from the Department of Labor to the U.S. Department of Justice. Additional stations were temporarily added along the Gulf Coast, Florida and the Eastern Seaboard during the 1960s after Fidel Castro triumphed in the Cuban Revolution, and that was followed by the Cuban Missile Crisis. The INS was decommissioned in March 2003 when its operations were divided between U.S. Customs and Border Protection (CBP), United States Citizenship and Immigration Services, and U.S. Immigration and Customs Enforcement.

 

Badge Of The United States Border Patrol - 1924-1940

U.S. Immigration Service - Under The Department Of Labor - 1924