…the U.S. government implemented an immigration enforcement initiative that was actually called “Operation Wetback”:

Operation Wetback was an immigration law enforcement initiative created by Director of the Immigration and Naturalization Service Joseph Swing. The program was implemented in May of 1954 by the U.S. Attorney General Herbert Brownell, and utilized special tactics to combat the problem of illegal border crossing and residence in the United States by Mexican nationals. Ultimately, the program came as a result of pressure from the Mexican government to stop illegal entry of Mexican laborers in the United States based largely on the Bracero Program. After implementation, Operation Wetback was met with allegations of abuse and suspension of certain civil rights of Mexicans that were captured and deported by U.S. Border Patrol

I wouldn’t go so far as to say we’ve progressed to a more “enlightened” point in our culture, though. I think the main lesson we, as a society at large, have learned is that programs like that shouldn’t have such overtly derogatory names.