In the late 1840s, the U.S. government seized control of California from the Republic of Mexico and immediately went to work on protecting the new land. Located in the middle of the San Francisco Bay, an island called Alcatraz was identified as a place of exceptional military utility. Nearly surrounded on all sides, it was ideally positioned to protect the entrance to the bay.

You may know Alcatraz as the so-called inescapable prison which housed Al Capone and George "Machine-Gun" Kelly, and then was immortalized in the film Escape from Alcatraz, but its history began long before.

On this episode, the Golden Gate National Recreation Area's Alcatraz Island, and its role during the civil war.

More info and music credits at nationalparkpodcast.com/alcatraz.