How high is current immigration to the United States in historical perspective?

Long-run US census data are used to track the foreign-born population (people not US citizens at birth, including naturalized and unauthorized migrants) from 1850 onward, comparing both absolute numbers and share of the total population. The foreign-born population reached about 50 million in 2024, the largest absolute count in the series. Historically the count rose from roughly 2 million in 1850 to 10 million by 1900, climbed until 1930, then fell for four decades to a low around 1970 before rising steadily since. Measured as a share of the total population, immigrants made up roughly 13-15% in the late 1800s, fell to just under 5% in 1970, and returned to about 15% by 2024 - so the current share matches the 19th-century peak even as the absolute number is unprecedented.

The composition of immigration has shifted markedly: turn-of-the-century immigrants were predominantly European (notably Germany and Ireland, with Canada a large non‑European source), whereas growth after 1970 has been driven by Latin America and Asia; in 2024 the top countries of birth are Mexico, India, and China. The census-based series aims to include unauthorized migrants but does not directly record legal status and can miss some people, so these totals indicate scale and origin shifts but do not measure yearly border crossings or enforcement outcomes.