Figure 3. Since the spike in personnel beginning in the 1980s, the vast majority of agents have been posted along the U.S.-Mexico border.

(Data compiled from Joseph Nevins, Operation Gatekeeper: The Rise of the “Illegal Alien” and the Making of the U.S.-Mexico Boundary (New York: Routledge, 2002), Appendix F, and U.S. Border Patrol Fiscal Year Staffing Statistics.)