De Diego resigned from the position in order to pursue independence. In 1904, he co-founded the Unionist Party along with Luis Muñoz Rivera, Rosendo Matienzo Cintrón and Antonio R. Barceló. De Diego was elected to the House of Delegates, the only locally elected body of government then allowed by the U.S., over which De Diego presided from 1904 to 1917. The House of Delegates was subject to the U.S. President's veto power and unsuccessfully voted for the island's right to independence and self-government. It petitioned against imposition of U.S. citizenship to Puerto Ricans in 1917, but the US granted citizenship to island residents. Despite these failures, De Diego became known as the "Father of the Puerto Rican Independence Movement."Articulos (Spanish)
