After graduating in law, in 1848 he became a magistrate and attorney general of the Grand Criminal Court of Naples; he was then appointed Undersecretary of the Interior and subsequently of Justice in the Troya government.

[3] He drafted the government's protest note addressed to King Ferdinand II on the parlous conditions of the kingdom.

After the fall of the liberal ministry and the king’s abrogation of the Constitution, Vacca was first arrested and then, in 1850, condemned to exile.

In 1859 King Francis II pardoned him and invited him to serve as Minister of Justice, but he refused.

[1][3] After the unification of Italy, Vacca was attorney general of the Court of Cassation of Naples, and in 1861 he was appointed senator by Victor Emmanuel II.