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 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...