The first wave of immigrants to the United States in the early nineteenth century was from England, Ireland, Germany, Scandinavia, and other northern European countries. Immigration dropped off sharply during the American Civil War (1861– 1865), but rapidly increased after the war’s end to levels not previously seen. Millions of Italians, Greeks, Russians, Slavs, and other eastern Europeans began arriving en masse. This second major wave of immigrants, known as the “Great Wave,” was different from anything Americans had ever seen before, and many Americans feared people from cultures so foreign to them.

Prior to the 1880s, roughly only 10 percent of all immigrants were from Italy, Spain, Greece, Russia, Poland, Hungary, Romania, and other eastern European countries. In 1907, when nearly 1.3 million immigrants arrived in the United States, almost 81 percent were from these countries, and only 19 percent were...