Recent politics is full of debates about erecting walls on the U.S.-Mexican border or barring Muslims from entering the U.S. But excluding groups of immigrants based on a particular background is nothing new—though the targets may change. It was in 1882 that Congress, for the first time in the history of the United States, passed legislation to prevent a specific ethnic group from entering the country. In effect from 1882 to 1943, the Chinese Exclusion Act forbade Chinese residents from …