Trump claimed ex-presidents told him they wished they built a wall. We now know he made it up.
https://migration.ucdavis.edu/mn/more.php?id=466
Operation Gatekeeper in San Diego - Migration News | Migration Dialogue
On October 1, 1994, the US Border Patrol assigned 200 additional agents to guard the 14 miles of border between the US and Mexico south of San Diego. The goal of Operation Gatekeeper is to make it impossible for aliens to avoid capture. Between the port of entry at Highway 5 and the ocean, there is a fence, high intensity lights, and three lines of agents, all designed to advertise to potential illegal entrants that illegal entry will result...
https://www.netflix.com/title/80107514
Border Security: America's Front Line | Netflix
This reality series chronicles the behind-the-scenes action as U.S. Customs and Border Protection agents safeguard the nation's crossings and ports.
https://en.wikipedia.org/wiki/Border_Security:_Canada%27s_Front_Line