[5] The first light house on the island was completed in 1854, and served the bay during its time as a Citadel and military prison.

It was replaced by a taller (95 feet (29 m) above mean sea level) concrete tower built in 1909 to the south of the original one which was demolished after it was damaged due to earthquake in 1906.

Even though the Native Indians of the San Francisco area are stated to be the original settlers on the island (they collected eggs from the large flock of birds that regularly gathered there), Alcatraz got its name during Spanish rule in 1775 when naval officer and explorer Juan de Ayala surveyed the harbor and the San Francisco Bay.

[6] The gold rush and the inherent risk of the choppy waters of the west coast prompted the urgent need for establishing lighthouses.

Congress recognized the need and passed suitable acts in the years 1851 and 1852 to build seven lighthouses on the West Coast to guide navigation.

The Alcatraz Lighthouse was the first to be completed in July 1853, making it the oldest major navigational light on the West Coast.

[5] The shipping involved a long sea voyage of 12,000 miles (19,000 km) from the East Coast going round the cape of South America.

In 1902, it was transferred to the Cape St. Elias Lighthouse in Alaska and replaced by a revolving fourth-order Fresnel lens, producing a white flash every five seconds.

[5][8] Similar "Cape-cod style" lighthouses, encircling the thick light brick tower, were built at Point Loma in San Diego, Point Pinos near Monterey and also on the Southeast Farallon Island about 30 miles (48 km) west of the San Francisco Strait.

[10] The three lighthouse keepers, known as "wickies", were dressed in prescribed formal uniforms which consisted of a "navy blue hat, sack coat, vest and trousers".

The keepers worked on an eight-hour shift with the beacon lighted all through the year; during day time the lens was covered and protected from sun rays.