How many undocument immigrants came into the country during Donald Trump's first term?
Executive summary
Border Patrol “encounters” between ports of entry during President Trump’s first term (February 2017–January 2021) totaled roughly 1.8 million, a commonly cited figure for people apprehended or otherwise detected crossing the southwest border during that period [1]. That number, however, is an operational tally and not a clean count of unique unauthorized entrants because it excludes many “gotaways,” visa overstays, and repeat crossers; different sources and metrics produce lower or higher estimates and experts disagree on the precise net change in the undocumented population [2] [3] [4].
1. What the headline numbers mean: 1.8 million “encounters” under Trump
The most direct and widely reported figure in contemporary coverage is that U.S. Border Patrol encountered people between ports of entry about 1.8 million times from February 2017 through January 2021, a cumulative total that agencies publish and politicians cite when describing migration flows in Trump’s first term [1]. That administrative total represents encounters—apprehensions and other detections—not a census of unique individuals, so treating 1.8 million as “how many undocumented immigrants came in” overstates the certainty of the count without further qualification [1].
2. Why encounters are an imperfect measure: repeats, gotaways, and overstays
Border operational data double-counts people who are caught multiple times and omits “gotaways” observed but not apprehended; government and press reports note that “gotaways” were a significant and separately tracked flow in later years (nearly 400,000 in the most recent fiscal year reported, 2021) and that visa overstays account for a large share of newly unauthorized people in some years—factors that complicate any simple summation of who “came in” [4] [5]. Congressional and DHS-related reporting also identifies roughly 1.1 million crossers in particular fiscal-year slices (FY2017–FY2020), another operational total that sits alongside the 1.8 million encounters figure and highlights how different counting windows/methods shift the picture [2].
3. Net population change vs. flow counts: different questions, different answers
Flow counts (apprehensions, encounters, gotaways) measure activity at the border; population-change estimates measure how many more or fewer undocumented residents live in the U.S. Experts and analysts have concluded Trump’s policies likely reduced legal immigration and altered enforcement, but they disagree about the size of any decline in the unauthorized population—some argue the undocumented population remained roughly steady, not dramatically lower, during his first term [3] [6]. Recent retrospective reporting stresses that enforcement numbers alone don’t settle whether the undocumented population grew or shrank because emigration, visa overstays, naturalizations, and data lags all matter [6] [7].
4. Mixed signals in later fact-checking and scholarship: roller‑coaster flows
Fact-checking outlets and policy scholars describe a “roller-coaster” of monthly apprehensions during Trump’s term—sharp lows and subsequent spikes—so single-year comparisons can mislead (for example, monthly apprehensions ranged from about 11,127 in April 2017 to 132,856 in May 2019) and that volatility has driven disputes over whether overall illegal immigration fell under Trump [8]. Independent reports and watchdogs further note that public claims about record deportations or removals were sometimes overstated relative to the underlying data and that comprehensive effects require longer-term study [9] [7].
5. Bottom line and limits of available reporting
The best-supported operational answer is that Border Patrol recorded roughly 1.8 million encounters between ports of entry during Trump’s first term, and other DHS-congressional tallies cite about 1.1 million crossers in overlapping fiscal-year slices, while “gotaways” and visa overstays add important—and less precisely measured—components to the total picture [1] [2] [4] [5]. No source in the provided reporting converts those operational flows into a definitive count of unique undocumented people who “came into the country” over the four-year span, and experts disagree about net population change, so any single-number answer must be framed as an estimate tied to the chosen metric rather than a final census [3] [7].