[3] The entity claims a unique tradition that unlike the rest of the state national guards, also includes the early American period that preceded the creation of the Thirteen Colonies.

[3] This claim is reflected in its first coat of arms which depicts the defeat of the British in the second Battle of San Juan and the patch worn by the 295th Regiment, designed by John Roqueña in 1953, which features a man wearing a morion.

[5] Since its early days, the units stationed in Puerto Rico used a yellow and red patch that features a guerite, similar to those at El Morro.

In San Juan three companies were organized under Federico Vall-Spinosa, Justo Barros, J. del Barril, R. Swigett, J. Doere, Lugo Vinas and F. Fano.

This organization failed due to existing US federal law, which prohibited the formation of any armed force within the United States and its territories without authorization from Congress.

[7] Due to the lack of belligerent invaders, the PRNG has participated in a number of functions such as coordination during natural disasters (mainly tropical storms, hurricanes, floods and droughts) repairing roads, bridges, telecommunication arrays and aqueducts.

The PRNG claims direct descent from the Puerto Rican militias that were founded after the Spanish Empire granted the island a governor and general captain.

[10] Its first large conflict emerged from the response to the Spanish–Taíno War of San Juan–Borikén, only years after the arrival of Juan Ponce de León and before the totality of Puerto Rico was under Spanish sovereignty.

[11] The Taínos of Borikén, led by Agüeybaná II were forced into labor and their territory threatened by the Spanish expansionism in the region, consequently deciding to begin a counteroffensive by killing Cristóbal de Sotomayor, the leader of a settlement built in southern Puerto Rico.

[12] Despite this setback, the local militias earned enough of a reputation for the next governor, Alonso de Mercado, to reportedly send back most of the soldiers that accompanied him in his voyage and rely on them for defensive purposes.

[12] In 1765, Marshall Alejandro O'Reilly who would later become known as "El Padre de las Milicias", reorganized the militias and created a group that was disciplined enough to fight in regular combat at the Anglo-Spanish War and be commended by the crown.

[15] In 1797, the British attempted another invasion, this time led by Ralph Abercrombie, but were defeated by a force that heavily depended on the local militias in the fourth Battle of San Juan.

[3] In 1868, amidst a growing pro-independence in the population that eventually lead to the Grito de Lares, the Spanish government decided to replace the mostly Puerto Rican quorum of the militias with an Institute of Volunteers that was completely composed of Spanish-born citizens.

[16] In 1906, a group of men led by Commissioner of Interior Lawrence H. Grahame decided that there was a need to create a national guard that mirrored those in the states in order to replace the militias.

[18] With the onset of World War I and the mobilization of the 373th, 374th and 375th regiments of the Regular Army, the need for a local military force became evident as some 20,000 men were trained in Camp Las Casas.

[21] On July 19, 1919, the United States Department of War informed Yager about the administration's intention of supporting a local reserve pursuant to the statutes of this law to create a permanent national guard that was capable of assisting the other branches of the military or working independently.

[52] In February 1934, Gen. George Leach, who oversaw Company A of the 295th, visited Puerto Rico and was surprised to see that the bayonets had been repaired motu proprio with local resources and their discipline, promoting him to pronounce during a speech that he had "inspected the national guards of the 48 states" and not seen one better prepared than the PRNG, going to the extent that if the president asked which was the best regiment for defense, it would be the 295th.

[54] On July 25, 1938, Irizarry was killed during an assassination attempt against colonial governor Winship in one of several confrontations between the government and the Puerto Rican Nationalist Party following the events of the Ponce massacre.

[56] The three regiments formed a brigade that was led by brigadier general Walter Short and was given jurisdiction over Puerto Rico in case of military action.

[59] On January 8, 1940, an emergency camp was held and a training exercise where an invasion of the northern coast of Puerto Rico was being invaded, in particular the municipalities of Arecibo and Vega Baja, and the 295th and 296th were tasked with repelling it.

[69] A group of 1,359 belonging to 295th Infantry Regiment were assigned to Campamento Tortuguero in Vega Baja, Puerto Rico where training was under seen by Esteves under Col. Miguel A.

[76] The 266th Regiment was given the task of guarding the Panama Canal Zone, both in the Atlantic and Pacific coasts, and participated in missions in Peru, Galapagos and Ecuador under Col. Francisco Parra Toro.

[82] Company Headquarters for the first and second natal lions were located in Mayagüez and Ponce, with Lieutenant Colonels Rafael Sepúlveda, Manuel Nazario and Invan Domínguez.

[100] Led by Col. César Cordero, who was given control of Camp Tortuguero, the regiment was assigned for training in anticipation for future deployment and waiting for orders from the General Headquarters of the Antilles Department.

[122] On February 21, 1960, commemorated as National Guard Day, the 65th Infantry Regiment was transferred from the Regular Army to the PRNG, in an activity where Gen. Cesár Cordero handed the unit's colors to Col. Rafael Rodríguez.

[122] On September 5, 1960, the PRNG was activated to attend a series of building and bridge collapses caused by floods brought by the adjacent passing of Hurricane Donna, which lead to the deaths of 149 civilians.

[132] Other municipalities treated during this time include Aibonito, Coamo, Orovovis, Vega Baja, Guánica, Ponce, San Juan, as part of yearly trainings, requests or emergent circumstances.

[139] Other activities included raising funds for civic organizations, specific constructions, disposing of garbage, building restorations, and cooperating with the Boy Scouts of America.

[145] On November 28, 1974, Hernández Colón activated the national guard again, this time in response to a strike being declared in the Puerto Rico Aqueducts and Sewers Authority.

[146] The following month, Tropica Storm Eloise passed near the North Coast of Puerto Rico, with a large number of guardsmen voluntarily joining the Civil Defense in the evacuation, clearing of debris, transportation and the management of Assistance Centers that followed.