Corregidor  comes from the Spanish word “corregir,” meaning to correct. One story  states that due to the Spanish  system wherein all ships entering Manila Bay were required to stop and  have their documents checked and corrected,  the island was called "Isla del Corregidor" (Island of the Correction).  Another version claims that the island was  used a penitentiary or correctional institution by the Spanish and came  to be called "El Corregidor." 
In early and  pre-hispanic times, it was likely populated by fishermen and no doubt  provided a base for pirates who  could easily launch an attack against any vessel entering Manila Bay.  During the Spanish era this tadpole-shaped  island was a signal station where bonfires were lit to alert Manila of a  home-coming galleon. Later on, Spaniards  built a lighthouse on the island. 
The Spaniards  set up a naval dockyard on the island in 1795. This was followed by a  naval hospital and a signal  station which was used primarily to warn Manila of approaching enemies.  In 1836 a lighthouse was built and in 1853  a stronger light was installed. This was replaced in 1897 and remained  in use until the outbreak of the Pacific War,  during which it was heavily damaged and rebuilt to the same  specifications. During the Spanish times, the small  town of San Jose emerged to become the seat of government on the island.  Later under the Americans, it evolved into  a small community with its paved streets lined with the houses of the  Philippine Scouts who constituted the bulk of  the garrison in Corregidor. 
After the  defeat of the Spanish forces by Admiral George Dewey in May of 1898,  Spain ceded Cuba, Puerto Rico, and the  Philippines to the Americans under the Treaty of Paris which was signed  on December 10, 1898. In 1903 a former  Spanish garrison building there was converted to a convalescent  hospital. The island was designated as a U.S.  Military Reservation in 1907 and the army post on Corregidor was named  Fort Mills, after Brig. Gen. Samuel M. Mills,  chief of artillery of the U.S. Army in 1905-1906. A regular army post  was later established in 1908.  
The following  year army engineers of “H” company, 2nd Battalion of the U.S. Corps of  Engineers began to build  fortifications on the island to secure the seaward approach to Manila  Bay. This was part of the planned "Harbor  Defenses of Manila and Subic Bay" due to the strategic location of  Corregidor. Concrete emplacements and bomb-proof  shelters were constructed and trails and roads were laid out on the  island. This engineer contingent left on  March 15, 1912, after laying down the groundwork to make Corregidor a  great military bastion. Thus began the  transformation of a small fishing village into a fortress and site of  one of the most heroic battles in the  history of war. 
The big guns of  Corregidor in 1941 were used in support of Filipino and American  defenders of Bataan until the  island itself was invaded by Japanese Forces. The restless pounding by  Japanese guns including intermittent  bombings reduced its defenses and compelled its surrender. On January  22, 1945, Corregidor was once again caught  in the fury of war as the Americans retook the island after a bloody  battle.