Among his many accomplishments was the introduction of a Bill to the Spanish legislature which established free commercial trade and public education in Puerto Rico.

He lived there with his parents, Tomas O'Daly and Maria de la Puente y Franco and his older brother and sister.

His father Tomas was a Colonel in the Spanish Army Corps of Engineers who was sent to Puerto Rico in the quest of revamping the El Morro fort then known as the Castle of Saint Phillip and was named chief engineer of modernizing the defenses of San Juan, which included the Castle of San Cristóbal.

While the war was taking place, the "Diputación Permanente del Reino" sort of the Council of the Regency, pending the kidnaping of the king, convoked the Spanish Parliament, which convened in Cadiz.

But O'Daly was a defender of the Spanish Constitution of 1812 and was considered a rebel and exiled from Spain by King Fernando VII in 1814.

While the 1820 revolt was successful in having king reinstate the Constitution, it failed miserably to supply the Royalists in South America who were running out of resources against England, Simon Bolivar and Jose de San Martin.

However, and due to his participation and fumble in the 1820 Revolt of the Colonels which meant the loss of the South American kingdoms, on May 15, 1824, Lieutenant General Miguel Luciano de La Torre y Pando, the governor of Puerto Rico issued an order for his arrest in the event that O'Daly returned to the island.

So, together with the rest of Puerto Rican statesmen, artists, military, clergy, etc., of international renown in their day in the Spanish Kingdoms (1500-1898), O'Dally, while one of the most important Spanish political and military figures of the early 19th century Napoleonic-Constitutional Crisis, is a forgotten and forsaken character in his native island.

The most that San Juan, his hometown, has done to honor his memory is the naming a third level street in a low-middle class income part of town of, the "Calle Demetrio O'Daly".