Which Border Patrol sectors and states saw the largest increases in undocumented crossings under Biden?
Executive summary
The largest increases in undocumented crossings under President Biden were concentrated along the Southwest border, with several Texas Border Patrol sectors—most notably the Del Rio area—highlighted by officials and reporting as sharply strained by higher encounter totals; nationwide encounter tallies show the Southwest accounted for the vast majority of crossings during his term [1] [2] [3]. At the same time, reporting and oversight briefs note notable activity on the northern border and a rise in “gotaways,” complicating any simple sector-by-sector ranking based on the material provided [3] [4].
1. Southwest border overall: the primary locus of increased encounters
Federal and policy reporting repeatedly place the Southwest border at the center of the rise in undocumented entries, with CBP and migration analysts recording millions of encounters there during the Biden years and the Migration Policy Institute estimating roughly 8.6 million migrant encounters on the Southwest border through October 2024 [1]. Congressional Republican summaries and committee fact sheets likewise emphasize that most encounters during the period were at the Southwest border, compiling national tallies in the multiple millions and pointing to sustained high monthly totals [3] [5].
2. Texas sectors—Del Rio singled out as overwhelmed
Among sectors, Texas received the most explicit attention in the provided reporting: Senator Cornyn’s office and other accounts describe the Del Rio sector as overwhelmed by high volumes that forced redeployment of agents, making Del Rio a focal example of where increases were most acute [2]. Reporting and imagery tied to the Rio Grande and Texas riverbanks reinforce that Texas sectors bore heavy operational pressure as crossings surged along that stretch of the border [6] [2].
3. Patterns within sectors: families, unaccompanied children, and repeat crossers
Analysts note that the composition of crossings shifted during the period, with spikes in family units and historically high encounters with unaccompanied children in particular years—figures that concentrated in certain sectors and complicated processing capacity [7] [1]. MigrationPolicy stresses that much of the Southwest total reflected repeated encounters and a mixture of nationalities and case types, indicating that high encounter numbers in specific sectors may partly reflect repeat crossers rather than a one-to-one increase in unique individuals per sector [1].
4. Northern border and “gotaways”: a different kind of increase
Not all increases were on the southern frontier; House committee reporting and other oversight materials flag higher activity along the northern border as well, where single adults increasingly cross and many attempts involve evading apprehension—a dynamic described as different in character from the mass group surrenders seen in parts of the Southwest [3]. CBP metrics on “gotaways” (detected but not apprehended crossings) rose during the period and are concentrated in both border regions, creating pockets of significant increases that do not always map neatly to sector apprehension statistics [4].
5. Political framing and data limits: where sources diverge
Republican congressional and campaign sources frame the increases as an “unprecedented crisis” and emphasize statewide and sector overloads using aggregated encounter and “gotaway” counts [2] [3] [5], while policy analysts and fact-checkers caution that encounter counts include repeat crossers, paroles at ports of entry, and transfers to other agencies, complicating direct comparisons across sectors or administrations [8] [1]. The provided reporting does not include a complete, authoritative sector-by-sector table showing percentage increases for every sector across the Biden term, limiting the ability to produce a definitive ranked list from these sources alone [1] [8].
6. Bottom line: Texas (notably Del Rio) and the Southwest saw the clearest, largest increases in operational strain
Synthesizing the sources, the most consistent finding is that increases were largest in Southwest sectors—especially Texas sectors like Del Rio—where both political and policy reporting document concentrated operational strain and very large encounter totals, while the northern border and “gotaways” accounted for important, though differently characterized, increases [1] [2] [3] [4]. The sources together make clear that any precise sector ranking requires CBP’s full sector-level encounter and gotaway time series, which are not supplied in the material provided here [1] [8].