Del Carril was elected to the assembly that approved the 1853 Argentine Constitution.
Enmities remaining from the Rosas era thwarted an opportunity to return to the Governor's post in San Juan, however, and despite his personal efforts, Buenos Aires lawmakers rejected the new constitution.
His belonging to the Buenos Aires-centric Unitarian Party and rapport with Urquiza (whom Buenos Aires distrusted) made del Carril an easy choice for the latter's running-mate in the elections that November, however, and their national unity ticket was elected handily in the electoral college.

President Urquiza took care to preserve balance in his government between the two camps, placing the Vice President as a counterweight to the Federalist Interior Minister (Home Secretary), Santiago Derqui.
Del Carril became the most prominent voice for Buenos Aires interests in the administration, and compounded with a falling-out with erstwhile allies in his native San Juan Province, this ultimately frustrated his hopes that Urquiza might support his 1860 presidential candidacy (support which was tantamount to victory).

Nominating Derqui instead, Urquiza's choice led to renewed conflict with Buenos Aires, and to Derqui's resignation and exile in 1861.
 National unity on the brink, del Carril negotiated a settlement between Urquiza and the leader of the Buenos Aires insurrection, General Bartolomé Mitre, and when the latter was elected President the following September, del Carril was appointed to the Argentine Supreme Court.

Del Carril was a conservative justice, and reliably voted in favor of the executive's frequent use of state of siege declarations and capital punishment.
This record helped him secure an appointment as Chief Justice in 1870 by Mitre's supporter and successor, President Domingo Sarmiento, and an uneventful tenure ended with his retirement in 1877.
He was again in the spotlight, however, after the 1881 publication by historian Ángel Carranza of correspondence between del Carril and Lavalle during the 1828 coup.
The letters revealed that del Carril pressed for the duly-elected Governor Dorrego's execution, advising Lavalle that claims of a fair trial should be concocted, adding that "if we should need to lie to posterity, we lie."
The former Vice President lived afterwards in seclusion, and died in his Buenos Aires home in 1883, at age 84.
Del Carril was elected to the assembly that approved the 1853 Argentine Constitution. Enmities remaining from the Rosas era thwarted an opportunity to return to the Governor's post in San Juan, however, and despite his personal efforts, Buenos Aires lawmakers rejected the new constitution. His belonging to the Buenos Aires-centric Unitarian Party and rapport with Urquiza (whom Buenos Aires distrusted) made del Carril an easy choice for the latter's running-mate in the elections that November, however, and their national unity ticket was elected handily in the electoral college.
President Urquiza took care to preserve balance in his government between the two camps, placing the Vice President as a counterweight to the Federalist Interior Minister (Home Secretary), Santiago Derqui. Del Carril became the most prominent voice for Buenos Aires interests in the administration, and compounded with a falling-out with erstwhile allies in his native San Juan Province, this ultimately frustrated his hopes that Urquiza might support his 1860 presidential candidacy (support which was tantamount to victory).
Nominating Derqui instead, Urquiza's choice led to renewed conflict with Buenos Aires, and to Derqui's resignation and exile in 1861.  National unity on the brink, del Carril negotiated a settlement between Urquiza and the leader of the Buenos Aires insurrection, General Bartolomé Mitre, and when the latter was elected President the following September, del Carril was appointed to the Argentine Supreme Court. 
Del Carril was a conservative justice, and reliably voted in favor of the executive's frequent use of state of siege declarations and capital punishment. This record helped him secure an appointment as Chief Justice in 1870 by Mitre's supporter and successor, President Domingo Sarmiento, and an uneventful tenure ended with his retirement in 1877. He was again in the spotlight, however, after the 1881 publication by historian Ángel Carranza of correspondence between del Carril and Lavalle during the 1828 coup. The letters revealed that del Carril pressed for the duly-elected Governor Dorrego's execution, advising Lavalle that claims of a fair trial should be concocted, adding that "if we should need to lie to posterity, we lie." The former Vice President lived afterwards in seclusion, and died in his Buenos Aires home in 1883, at age 84.
Salvador María del Carril