The ten-week Spanish-American War started as a result of American intervention in the Cuban War of Independence and eventually spilled over into the Pacific, resulting in the Phillipine Revolution and the Phillipine-American War.
Spain's defeat led to the loss of much of its empire, including Cuba, Puerto Rico and the Philippine Islands.
It triggered a wave of artistic expression and political re-evaluation as the country sought to come to terms with its new status in world affairs.
According to Lisa Crunk, head of the US Naval History and Heritage Command's photo archives, the discovered photos of the conflict are 'amazing'.
"The plates were individually wrapped in tissue paper and include full captions and dates, which were likely prepared by the photographer, Douglas White," she said.
"The glass plates are in perfect condition and housed in a large wooden box with a leather strap, which likely allowed for it to be carried by the shoulder."
Further enhancing the provenance of the collection was an etching on the cover of the box stating that the slides were taken 'In and Around Manila' during the 'Spanish - American War - 1898 and Philippine Insurrection' by 'Douglas White, War Correspondent'.
"Research on Mr. White discovered that he was a special war correspondent of the San Francisco Examiner during the Philippine War," said Crunk.
The box of glass plates were found in an archival storage space on February 5th as the photo archive team was preparing for a major renovation project. The entire collection is being rehoused into new archival enclosures and shelving units.
The discovery was made by archivists Dave Colamaria and Jon Roscoe during a survey phase of the renovation project.
"Once it was realized what they had uncovered, there was tremendous excitement amongst the staff, especially the historians! The images are an amazing find, though they were never really lost - they were simply waiting to be re-discovered," she said.
Plans for the photo collection include high resolution digitization, cataloguing and eventual exhibition on the organization's website.