Francisco Domingo Díaz participated with the rank of colonel in the Battle of Angaco in the Federalist Cazadores Battalion, composed of troops from San Juan.

The reforms undertaken during his administration covered a wide spectrum: justice, politics, education, military and culture.

Soon after taking office, Díaz appointed a commission to undertake the impeachment trial of Nazario Benavidez, the outgoing governor.

During his previous government, Benavidez had asked Maradona for documents to justify his tenure as vicar of the Diocese of San Juan de Cuyo.

Maradona replied that he ruled as a vicar in vacancy, delegated by the Bishop José Manuel Quiroga Sarmiento.

In mid July 1856 the crisis erupted and Díaz issued a decision that denied the legitimacy of Maradona as bishop and ordering sanctions against clergy who obeyed him.

The constitution was not innovative in its provisions compared to those already existing in other provinces, but omitted the preamble invoking God as the source of all reason and justice and the maintenance of the cult suppressed by the state.

On 17 March 1857 there was a military revolution that put Nazario Benavidez in the office of acting governor, replacing Francisco Diaz who was accused of having turned towards the liberal sector of Buenos Aires.

The Confederation Argentina, which supported Benavidez, promptly sent a commission that assumed the government and called elections for governor.

Juan Saá took over the government and appointed Lieutenant Colonel Filomeno Valenzuela of the National Guard as governor.

With the defeat of the Confederacy Argentina in the Battle of Pavón (17 September 1861) Diaz left the government of the province and fled at the approach of the Liberal troops.