The first major immigration wave since the United States became a nation started in the 1820s and lasted until a recession in the late 1870s. The wave brought about 7.5 million immigrants, primarily from northern and western Europe. Specifically, about a third of those were Irish fleeing that country’s potato famine.
America, still booming from the Industrial Revolution, offered opportunity.
“When we look at history, you see that immigration goes up in times of economic prosperity and down when the economy is not doing so well,” said Michele Waslin, senior policy analyst with the Washington, D.C.-based Immigration Policy Center. The influx spurred opposition from many citizens, who said Irish immigrants were taking Americans’ jobs and opposed the immigrants’ religion. Politicians demanded laws to make it harder for foreigners to become U.S. citizens.
In 1875, the U.S. passed its first restrictive immigration law. It prevented prostitutes and convicts from entering the country.

See the full article from “Arizona Republic”