The man elected president in 1868—Ulysses S. Grant—was determined to change the way many of his fellow Americans understood citizenship. As he saw it, anyone could become an American, not just people like himself who could trace their ancestry back eight generations to Puritan New England. Grant maintained that the millions of Catholic and Jewish immigrants pouring into the country should be welcomed as American citizens, as should the men, women, and children just set free from slavery during the …