It’s possible to search for Alcatraz Prison inmates and employees in the 1940 U.S. population census.
Alcatraz Prison was a federal prison located on an island in San Francisco Bay. The Spanish explorer who first sited the island noted that it was literally covered with California brown pelicans (the name Alcatraz is in fact an archaic Spanish word for pelican). The waters of the bay surrounding the island were notable for their icy temperature, strong currents, and ever-present sharks. Alcatraz was used as a fort and military prison before becoming a federal prison in August 1934. Attorney General Robert F. Kennedy ordered its closure in March 1963 (due to its high cost of operation and deteriorating buildings).
On the Ancestry Library Edition (Ancestry LE) landing page you will find a list of available U.S. population schedules in the lower right corner. Select 1940, and you will be presented with a search screen. Try the following search:
Lived In: San Francisco, San Francisco, California, USA (Exact)
Keyword: -AZ (Exact)
This Keyword search works because inmates in the Relation to Head of Household category are identified in this manner:
McGlone, John 252-AZ
In the Alcatraz census schedules, employees are listed first, followed by inmates. 521 Alcatraz inmates are listed in the 1940 census.
You can use Ancestry LE at Central Library or any of our branches.