When do you see a major shifts in immigration

Irish Immigrant Wave
1815: Peace is re-established between the United States and Britain after the War of 1812. Immigration from Western Europe turns from a trickle into a gush, which causes a shift in the demographics of the United States. This first major wave of immigration lasts until the Civil War.

Between 1820 and 1860, the Irish—many of them Catholic—account for an estimated one-third of all immigrants to the United States. Some 5 million German immigrants also come to the U.S., many of them making their way to the Midwest to buy farms or settle in cities including Milwaukee, St. Louis and Cincinnati.
1849: America’s first anti-immigrant political party, the Know-Nothing Party forms, as a backlash to the increasing number of German and Irish immigrants settling in the United States.

1875: Following the Civil War, some states passed their own immigration laws. In 1875 the Supreme Court declares that it’s the responsibility of the federal government to make and enforce immigration laws.

Chinese Exclusion Act

1880: As America begins a rapid period of industrialization and urbanization, a second immigration boom begins. Between 1880 and 1920, more than 20 million immigrants arrive. The majority are from Southern, Eastern and Central Europe, including 4 million Italians and 2 million Jews. Many of them settle in major U.S. cities and work in factories.