The American Legion is a federally chartered veterans organization that supports veterans’ issues and engages in other community projects. The American Legion Mid-Pacific Post No. 1 was founded in Guam in 1930 under Naval Governor Willis Bradley. When the Guam Museum was first established in 1932, Governor Edmund S. Root authorized the use of a small building adjacent to the Plaza de España’s historic grounds fronting and surrounding the Governor’s Palace. The newly formed American Legion offered to manage it. Hiram W. Elliot, post commander, and Naval Chaplain Francis Lee Albert. Elliot hired Joaquin T. Aguon to help with the collections.

At the opening ceremony of the Museum, a small collection of artifacts were donated which formed the foundation for a CHamoru exhibit. The Legionnaires spent their own time and funds operating the museum until 1936 when the Naval Government took over museum operations. The building was destroyed during the bombing of Hagåtña in World War II.