How has the number of naturalized citizens in Congress changed over recent sessions?
Executive summary
The number of naturalized citizens serving in Congress has been small but visible: reporting counted 18 foreign‑born members in the 117th Congress (some of whom were naturalized) and analysts in 2022 said at least 14 immigrant members would return to that Congress [1]. Official House and Senate rosters list foreign‑born members for each session, but available sources do not provide a single, consistent time series that enumerates "naturalized citizens in Congress" across recent sessions [2] [3] [1].
1. What we can say with confidence: foreign‑born members are tracked but definitions vary
Congressional and outside trackers record lawmakers born outside the United States, but these lists mix those who were naturalized with people who acquired citizenship at birth through a U.S. parent — a distinction that matters for your question. The House Clerk publishes a roster of "Foreign‑Born in the UNITED STATES HOUSE OF REPRESENTATIVES" for the 119th Congress [2], and the Senate maintains its own page, "Senators Born Outside the United States" [3], but neither source presents a cleaned, multi‑session count exclusively of naturalized members [2] [3].
2. Recent snapshots: small numbers, measurable presence
Journalistic summaries and research briefs provide session‑level snapshots. VOA reported that the 117th Congress included 18 members born outside the United States, and noted at least 14 immigrant members were set to return to a subsequent Congress [1]. Those figures show that foreign‑born lawmakers — some naturalized, some U.S. citizens at birth — make up a small but steady portion of Congress [1].
3. Why trends are hard to measure from public sources
Available reporting and official pages list places of birth and biographical details but do not consistently label whether a foreign‑born member is a naturalized citizen versus a citizen at birth, nor do they produce a continuous time series across sessions. The House Clerk PDF for the 119th provides a roster with places of birth, useful for session snapshots, but not a decade‑long trendline of naturalized membership [2]. The Senate file likewise catalogs foreign‑born senators but doesn’t separate naturalized status in a consistent, historical dataset [3].
4. What related federal data tells us about the larger context
Naturalization flows into the electorate and potential candidate pools are documented separately by DHS and CRS. DHS produces annual naturalization flow reports showing how many people naturalize each year [4]. The Congressional Research Service’s recent naturalization policy brief documents processing volumes and backlogs — for example, roughly 536,000 N‑400 applications were pending as of March 31, 2025 — indicating the pool of newly naturalized Americans has been large even as the number of naturalized members of Congress remains comparatively small [5] [6].
5. Competing narratives and political uses of the data
Immigration policy debates have elevated questions about birthright and naturalization in ways that make lawmaker nativity politically salient. Legislative initiatives such as the Born in the USA Act and other proposals aim to alter birthright rules and have been cited as part of a broader narrative on who qualifies as American [7] [8]. Advocacy groups and courts emphasize that naturalized citizens enjoy the same constitutional protections as native‑born citizens — a legal point highlighted by the Brennan Center’s review of denaturalization limits [9]. These competing framings mean counts of "immigrant" or "naturalized" lawmakers are often used selectively by partisans [7] [9].
6. What to look for if you want a precise trend line
To build a rigorous, session‑by‑session trend of naturalized members you will need to (a) compile official rosters from the House Clerk and Senate for each Congress, (b) verify each foreign‑born lawmaker’s citizenship acquisition method from biographical sources, and (c) distinguish naturalized citizens from those who were citizens at birth. The House and Senate pages are the primary raw sources [2] [3], but that work is not present in the materials reviewed here (available sources do not mention a completed multi‑session dataset).
7. Bottom line
Foreign‑born members of Congress are consistently present in low double‑digit numbers in recent sessions, but the public sources provided do not produce a ready‑made, sessional time series that isolates naturalized citizens alone. Use House and Senate rosters for session snapshots [2] [3], supplement with biographical research for citizenship‑at‑birth versus naturalization status, and consult DHS/CRS reporting for context on the larger pool of newly naturalized Americans [4] [6].