1. After the prison stood dormant for six years, Native American activists occupied Alcatraz.
Following two previous brief occupations, a group of nearly 100 Native American activists, led by Mohawk Richard Oakes, took over the island in November 1969. Citing an 1868 treaty that granted unoccupied federal land to Native Americans, the protestors demanded the deed to Alcatraz in order to establish a university and cultural center. Their proclamation included an offer to purchase the island for “$24 in glass beads and red cloth”—the same price reportedly paid by Dutch settlers for Manhattan in 1626. Federal marshals removed the last of the protestors in June 1971, but some of their graffiti remains. When the National Park Service recently rebuilt an Alcatraz water tower, it made sure to repaint the red graffiti that read “Peace and Freedom. Welcome. Home of the Free Indian Land.”

2. Military prisoners were Alcatraz’s first inmates.
Once the Gold Rush of the 1840s turned San Francisco into a boomtown, Alcatraz was dedicated to military use. The U.S. Army began incarcerating military prisoners inside the new fortress in the late 1850s. During the Civil War, prisoners included Union deserters and Confederate sympathizers. The cells were also used to imprison Native Americans who had land disagreements with the federal government, American soldiers who deserted to the Filipino cause during the Spanish-American War and Chinese civilians who resisted the Army during the Boxer Rebellion.

3. Alcatraz was home to the Pacific Coast’s first lighthouse.
When a small lighthouse on top of the rocky island was activated in 1854, it became the first of its kind on the West Coast of the United States. The beacon became obsolete in the early 1900s after the U.S. Army constructed a cell house that blocked its view of the Golden Gate. A new, taller lighthouse replaced it in 1909.

4. The country’s worst criminals were not automatically shipped to Alcatraz.
The convicts housed in Alcatraz were not necessarily those who had committed the most violent or heinous crimes, but they were the convicts most in need of an attitude adjustment–the most incorrigible and disobedient inmates in the federal penal system. They had bribed guards and attempted escapes, and a trip to Alcatraz was intended to get them to follow the rules so that they could return to other federal facilities.

5. It was possible to swim to shore.
Federal officials may have initially doubted that any escaping inmates could survive the swim to the mainland across the cold, swift waters of San Francisco Bay, but it did happen. In 1962, prisoner John Paul Scott greased himself with lard, squeezed through a window and swam to shore. He was so exhausted upon reaching the foot of the Golden Gate Bridge that police discovered him lying unconscious in hypothermic shock. Today, hundreds complete the 1.5-mile swim annually during the Escape from Alcatraz Triathlon.