In the 1930s, the Los Angeles Welfare Department decided to start deporting hospital patients of Mexican descent. One of the patients was a woman with leprosy who was driven just over the border and left in Mexicali, Mexico. Others had tuberculosis, paralysis, mental illness or problems related to old age, but that didn’t stop orderlies from carrying them out of medical institutions and sending them out of the country.

These were the “repatriation drives,” a series of informal raids that took place around the United States during the Great Depression. Local governments and officials deported up to 1.8 million people to Mexico, according to research conducted by Joseph Dunn, a former California state senator. Dunn estimates around 60 percent of these people were actually American citizens, many of them born in the U.S. to first-generation immigrants. For these citizens, deportation wasn’t “repatriation”—it was exile from their country.

The logic behind these raids was that Mexican immigrants were supposedly using resources and working jobs that should go to white Americans affected by the Great Depression. These deportations happened not only in border states like California and Texas, but also in places like Michigan, Colorado, Illinois, Ohio and New York. In 2003, a Detroit-born U.S. citizen named José Lopez testified before a California legislative committee about his family’s 1931 deportation to Michoacán, a state in Western Mexico.

“I was five years old when we were forced to relocate,” he said. “I…bec[a]me very sick with whooping cough, and suffered very much, and it was difficult to breathe.” After both of his parents and one brother died in Mexico, he and his surviving siblings managed to return to the U.S. in 1945. “We were lucky to come back,” he said. “But there are others that were not so fortunate.”

The raids tore apart families and communities, leaving lasting trauma for Mexican Americans who remained in the U.S. as well. Former California State Senator Martha M. Escutia has said that growing up in East Los Angeles, her immigrant grandfather never even walked to the corner grocery store without his passport for fear of being stopped and deported. Even after he became a naturalized citizen, he continued to carry it with him.