Alcatraz Island was discovered in 1775 by Spanish explorer, Juan Manuel de Ayala. He named it La Isla de los Alcatraces, which translates to the Island of the Pelicans, as these birds inhabited it in great numbers. It wasn't until 1850 when then President Milard Fillmore claimed it for military use and built a fortress on the island with many cannons in order to protect San Francisco Bay. The island also became home to the first working lighthouse on the West Coast.

The military began to house military prisoners there in the late 1850's and during the Civil War, it held prisoners that were Confederate sympathizers. It also held citizens who were accused of treason during the Civil War. The military prison also held Native American Indians who were deemed rebellious and in 1895, nineteen Hopi Indians from the Arizona Territory were sent to Alcatraz over land disputes with the government. Alcatraz also received a lot of prisoners from the Spanish-American War.

In the early part of the 20th century, the prison was made bigger by inmate labor which included a new 600 cell building, a hospital, a mess hall, as well as a few other prison buildings and the new construction was completed in 1912. At that time, Alcatraz boasted being the world's largest reinforced concrete building. In 1933, the military gave the island prison to the federal government, the United States Justice Department, to be more exact, as the justice department needed a more secure prison for its more troublesome and dangerous inmates. On July 1, 1934, Alcatraz opened for business under the Bureau of Prisons. Alcatraz then held anywhere between 260 and 275 prisoners at any given time.

Some famous, or infamous, prisoners held there included the likes of murderer Robert Stroud who was transferred there from Leavenworth prison in Kansas. He was known as the Birdman of Alcatraz, even though he could not have birds as pets there like he could in Leavenworth.

Another infamous inmate was the leader of Chicago's Outfit, Al Capone. Capone was sent there from Atlanta, Georgia because in the prison in Atlanta, Al Capone still ran the Outfit from his cell. He wouldn't be able to do this at Alcatraz.

“Public Enemy Number One”, Alvin Karpis spent over 25 years in the prison and “Machine Gun” Kelly spent the better part of 17 years there.

There have been 14 prison escape attempts involving 36 prisoners totaled. Of the 36 prisoners who attempted escape from Alcatraz, 23 were recaptured, 6 were shot an killed. 2 had drowned and 5 went missing and presumed drowned. One of these escape attempts was immortalized in the movie, Escape From Alcatraz, starring Clint Eastwood. His character was one of the five men that were presumed drowned but his body was never recovered.

The cost of running the prison soon became too much for the Bureau of Prisons as food and supplies had to be shipped in to the island at great expense and the salt air from the ocean soon took its toll on the buildings as the concrete began to crumble so it was officially closed as a prison in 1963.

In 1973, Alcatraz was opened to the public to come and visit as it had become part of the Golden Gate Recreation Area and at least one million visitors flock to Alcatraz each year. There is also a triathlon held there each year in which hundreds of athletes participate in the 1.5 mile swim from the island to San Francisco and then an 18 mile bike ride, culminating with an 8 mile run.