The petition failed because the U.S. Constitution prohibits the formation of any armed force within the United States and its territories without the authorization of Congress.

[5] Puerto Ricans served in the "Porto Rico Regiment" (later renamed 65th Infantry Regiment) as part of the regular United States Army during World War I, many of which received their military training at Camp Las Casas in Santurce a sector of San Juan, Puerto Rico.

Esteves' efforts were successful and with the approval of the Governor and the Insular Legislature, the Puerto Rican National Guard was organized in 1919.

[7] In 1919, Governor Yager named Major John A. Wilson (U.S. Army) the first adjutant of Puerto Rico.

As adjutant general, he was the Governor's senior military adviser and oversaw both state and federal missions of the Puerto Rico National Guard.