In a report prepared for the United States Census Bureau by demographers Thomas Gryn and Amy Smith, the foreign-born population of our country reached a record high of 50.2 million in 2024. The historical analysis is part of the Bureau’s ongoing “America Counts” series commemorating the 250th anniversary of the United States and the Bureau’s demographic record-keeping since 1790. The Bureau’s definition of “foreign-born” encompasses naturalized U.S. citizens, lawful permanent residents, humanitarian migrants, temporary visa holders (such as international students), and unauthorized migrants.
The milestone marks the evolution in how the nation’s population has shifted over the past 175 years. Census takers first began tracking place of birth in the 1850 Census. Today, immigrants and foreign-born residents account for 14.8% of the country’s 340.1 million total population—matching the previous percentage record set in 1890.
While the national foreign-born share is 14.8%, the Arrowhead region remains largely non-foreign-born. Cook County’s 3.5% compared to Lake County’s 1.3% reflects a small mix of international workers in the local hospitality/tourism industry and its proximity to the Canadian border. Both counties remain far below the historic waves of European immigration that settled the North Shore in the late 19th and early 20th centuries.
In 1850, the Census Bureau counted 2.2 million foreign-born residents; 92.2% of them came from Europe. In the 1850s, our country had no numerical limits, no visa requirements, and no country quotas for immigration. If our ancestors could afford the fare and survive the voyage across the ocean, they could get off the ship and legally live in the U.S.
In the 1920s—via the Emergency Quota Act of 1921 and the National Origins Act of 1924—the U.S. introduced national origin quotas, explicitly designed to favor Northern/Western Europeans and restrict Southern/Eastern Europeans and Asians.
Following the passage of the landmark Immigration and Nationality Act of 1965, which abolished origin quotas in favor of family reunification and skilled labor, immigration patterns shifted dramatically.
Latin America now represents over half of the foreign-born population, at 51.4%. Asia represents the second-largest group at 30.8%, fueled by refugee flows following the Vietnam War and the growing demand for highly skilled tech and professional labor since the 1970s. Europe now accounts for just 9.7%, and Africa represents 5.9%.
According to the reports, the foreign-born share in the population rose from less than 10% in 1850 to its peak of almost 15% in 1890. The increase was fueled by European industrial migration and the need for workers in a rapidly growing agricultural and industrial economy here. Post-WWI restrictive legislation and economic shifts led to a steady decline in the foreign-born share of the population over half a century, bottoming out at 4.7% in 1970.
Over the past five decades, steady immigration from Latin America and Asia has rebuilt the foreign-born population to its current peak of 50.2 million.
The report, titled “Measuring Foreign-Born Population Over Nation’s 250-Year History,” can be found at the Census Bureau website census.gov/library
