How many illegal aliens entered USA between 2009 and 2016
Executive summary
Available government and academic estimates do not produce a single, undisputed tally of how many people “entered illegally” between 2009 and 2016; instead, the literature shows that illegal border crossings fell sharply by 2009, visa overstays became a growing share of the unauthorized population, and the total undocumented population hovered near ~11 million—implying limited net growth from new illegal entries over that period [1] [2] [3].
1. What the question actually asks and why it’s hard to answer
“Asking how many illegal aliens entered the U.S. between 2009 and 2016” can mean different things—raw apprehensions at the border, estimated unauthorized arrivals (including undetected entries), or net increases in the undocumented resident population—and those measures are produced by different methods with different biases, so no single source in the record provides an undisputed headcount for that specific interval [4] [5] [2].
2. Trends in entries and the changing mix of arrival modes
Scholars and government statistics agree that physical border crossings declined sharply through 2009 from earlier peaks, and that by the 2010s visa overstays accounted for a larger share of the growth in the unauthorized population than illegal land crossings; one synthesis notes that from 2016–2017 overstays accounted for 62 percent of newly undocumented people, reflecting a longer shift visible through the 2010s [1] [2] [3].
3. What the population totals tell us about net arrivals from 2009–2016
The best-known series—Pew, DHS/OIS and Center for Migration Studies—show the total unauthorized population at roughly 12.0 million in 2007, declining to about 11.0–11.4 million by 2009 and remaining at or near ~11 million through the mid‑2010s; that near‑stasis of the resident undocumented population implies that arrivals and departures (voluntary returns, removals, adjustments to legal status, and deaths) largely offset one another during 2009–2016 rather than producing large net increases in resident undocumented population [2] [6] [7].
4. What direct arrival estimates or components-of-change studies say (and do not say)
Component studies and DHS tabulations can estimate arrivals by period of entry, but the sources provided do not include a single, authoritative tally labeled “illegal entries 2009–2016”; academic work shows arrivals peaked earlier (late 1990s) and declined through 2009, and DHS/CMS reporting documents substantial uncertainty in year‑to‑year components because departures offset arrivals and household surveys undercount recent cohorts—facts that make a simple cumulative arrival number for 2009–2016 elusive in the public record cited here [8] [9] [10].
5. Alternative estimates and contested claims
A demographic model published by researchers linked to Yale argued that conventional counts understate totals and implied larger historic flows up to 2016, but that study is contested and does not translate into a consensus annual or period‑specific entry count for 2009–2016; anti‑ and pro‑immigration commentators therefore sometimes cite very different numbers based on differing methodologies—household survey residuals, demographic modeling, or DHS administrative series—so readers should expect methodological disagreement rather than a single definitive number [11] [2].
6. Bottom line and limits of available evidence
There is no single, authoritative figure in the cited reporting equal to a precise count of people who “entered illegally” between 2009 and 2016; instead, multiple sources converge on the point that illegal border crossings had fallen by 2009, visa overstays grew in importance, and the overall undocumented population remained around ~11 million—together suggesting that net new illegal entries during 2009–2016 were modest and largely offset by departures, but the exact gross number of entries cannot be determined from the provided sources [1] [3] [2].