Between 1892 and 1954, millions of immigrants passed through the threshold of Ellis Island and became American citizens. From Ellis Island, these immigrants spread out all over the country. Many helped build the U.S. infrastructure and helped make the country one of the greatest in the world. Readers will view numerous primary sources surrounding Ellis Island and the people who visited the immigration center. These sources include letters, paintings, photographs, maps, and more. In addition, sidebars prompt readers to think critically about the primary resources and to answer essential questions about them.