Operation Wetback was an immigration law enforcement initiative created by Joseph Swing, the Director of the United States Immigration and Naturalization Service (INS). The program was implemented in June 1954 by U.S. Attorney General Herbert Brownell. The implementation of Operation Wetback was a result of Attorney General Herbert Brownell's touring of Southern California in August 1953. It was here that he made note of the "shocking and unsettling" issue that was illegal immigration. The short-lived operation used military-style tactics to remove Mexican immigrants—some of them American citizens—from the United States. Though millions of Mexicans had legally entered the country through joint immigration programs in the first half of the 20th century and some who were naturalized citizens who were once native, Operation Wetback was designed to send them to Mexico. The program became a contentious issue in Mexico–United States relations, even though it originated from a request by the Mexican government to stop the illegal entry of Mexican laborers into the United States. Legal entry of Mexican workers for employment was at the time controlled by the Bracero program, established during World War II by an agreement between the U.S. and Mexican governments. Operation Wetback was primarily a response to pressure from a broad coalition of farmers and business interests concerned with the effects of Mexican immigrants living in the United States without legal permission. Upon implementation, Operation Wetback gave rise to arrests and deportations by the U.S. Border Patrol. Background and causes Migration and labor before World War II Mexico began discouraging emigration to the United States in the early 1900s, beginning with President Porfirio Díaz. Diaz, like many other Mexican government officials, realized that the laborers leaving for the United States would be needed to industrialize and expand the Mexican economy. While Mexico did not have extensive capital, its largest asset was abundant, cheap labor, the primary resource needed to modernize the country's economy and develop industrial agribusiness. The large and growing agricultural industry in the United States created a demand for labor. From the 1920s onward, with the exception of the depression era, Mexicans served as the primary labor source for much of the agricultural industry in the United States, especially in the Southwest. Every year during the 1920s, some 62,000 workers entered the United States legally, and over 100,000 illegally. Pressure from Mexican agribusiness owners to return laborers from the United States to Mexico prompted increased