A group of federal prisoners classified as “most dangerous” arrives at Alcatraz Island, a 22-acre rocky outcrop situated 1.5 miles offshore in San Francisco Bay, on August 11, 1934. The convicts—the first civilian prisoners to be housed in the new high-security penitentiary—joined a few dozen military prisoners left over from the island’s days as a U.S. military prison.

Federal prisoners land on Alcatraz