Citizenship and Immigration Statuses of the U.S. Foreign-Born Population [April 9, 2021] [open pdf - 667KB]
From the Document: "The U.S. foreign-born population consists of individuals living in the United States who were not U.S. citizens at birth. An estimated 44.9 million foreign-born people live in the United States, representing 13.7% of the total U.S. population in 2019 (the most recent data from the American Community Survey [ACS]). The proportion of foreign-born has changed over time. The 1920 percentage of foreign-born (13.2%) was similar to current levels, then declined over the next five decades, reaching a low of 4.7% in 1970. Over the last five decades, the proportion has increased (Figure 1)."
CRS In Focus, IF11806
Congressional Research Service: https://crsreports.congress.gov/