Catalina Island, 30 miles off the coast of Los Angeles, California, inhabited by the Tongva people for thousands of years, and — in the 1800s — a favorite place for otter hunters, gold prospectors, and a hideout for pirates, is not specifically named in the 1848 Treaty of Guadalupe Hidalgo, the agreement in which Mexico cedes what we now call the Southwest, delineating the modern border between Mexico and the U.S.

On this day in 1972, 26 Brown Berets, a U.S. Chicano-rights group, occupy a bluff on the island overlooking a resort. They erect a large Mexican flag and set up a camp, Campo Tecolote, and persist with dwindling resources for three weeks, before L.A. county police escort them from the island.

In 1978, the Mexican government explicitly recognizes U.S. sovereignty over Catalina.