In 1934, but it was a Union fort in the civil war so it has been around along time. The first people it held as a prison was in 1873 and they were Native American. Nineteen were Hopi who refused to...
Alcatraz Island had only one facility on it. It was named Alcatraz Prison. Prior to that is was a fortification.
No. It is no longer used as a federal penitentiary and is operated by the US Park Service as a national park and tourist site.
It is located in San Fransisco Bay California.
You can learn all you want to know about the former Alcatraz Federal Pe3nitentiary at this site. See: http://www.alcatrazhistory.com/