On December 14, 1861, he married María del Carmen Susana Rodríguez Viana in the Church of San Nicolás de Bari, in Buenos Aires, and they had ten children.

In 1864, he was elected member of the Argentine Chamber of Deputies for the province of Buenos Aires and presented a bill to name the City of Rosario as the nation's capital, which would be approved but vetoed by the executive power.

In 1870 he was elected National Senator and in 1871 President Sarmiento sent him to Asunción to negotiate the peace treaty that ended the War of the Triple Alliance against Paraguay.

Since the defeat of 1893, and even more since the division between "bernardistas" and followers of Hipólito Yrigoyen, no one seriously considered the Unión Cívica Radical as a party with the possibility of accessing power.

But, suddenly, the UCR reappeared showing a political and territorial organization far superior to that of the ruling party, and a great revolutionary decision, in the radical revolution of 1905, in which several units of the Army were involved.

Exploded on February 4 of that year, it was relatively successful in Buenos Aires, Rosario, Córdoba, Bahía Blanca and Mendoza, but was quickly put down.

On August 11, 1905, Quintana and his wife, Susana Rodríguez Viana, suffered an attack against their lives, when Salvador Planas y Virella, a Catalan anarchist, shot at the presidential vehicle, but he could not carry out his task due to a failure in the pistol he used.

On January 6, 1911, he fled the Buenos Aires National Penitentiary with the anarchist Francisco Solano Regis, who had attacked President José Figueroa Alcorta, Quintana's successor.