At the age of 15, di Rudio left to join the Italian patriots during the uprising in 1848, and participated in the defense of Rome, and, later of Venice, against the Austrians.

On January 14, 1858, during a visit to the Salle Le Peletier of the Paris Opera, three bombs were thrown at the royal procession of Emperor Napoleon III.

Four men were arrested: Felice Orsini, the leader of the plot, Giuseppi Pieri, Antonio Gomez, and a Portuguese beer salesman named "Da Selva," who turned out to be di Rudio.

Di Rudio was initially condemned with Orsini and Pieri, but someone pleaded clemency for him and the sentence was commuted to life on Devil's Island.

After his Civil War service, DeRudio requested appointment to the Regular Army and received his commission as 2nd lieutenant in the 2nd Infantry Regiment on August 3, 1867.

But about a month later, he was back in uniform, where he remained until he became unassigned on April 17, 1869, as a result of the reduction of the size of the Army from 45 to 25 infantry regiments.

His company dismounted and fought in skirmish line against the Hunkpapa and Oglala warriors who rushed to defend their village from Reno's attack.

Under pressure from growing numbers of warriors, Reno ordered a retreat back across the river, where DeRudio lost his horse and was left behind in the timber on the western bank.

For thirty-six hours, DeRudio and Private Thomas O'Neill remained hidden, alternating hope and despair while witnessing the mutilation of dead soldiers by enraged Lakota women.

He had been scolded by Custer for accepting the present, and, perhaps as a matter of spite, had not surrendered his issued saber when the others had been packed up at the Powder River Depot.

DeRudio commanded a re-constituted Company E during the Nez Perce War of 1877, assigned to reinforce Lt. Gustavus Doane's detachment of the 2nd Cavalry patrolling the mountains after the Battle of Big Hole.

DeRudio continued service with the 7th Cavalry, was promoted to captain on December 17, 1882, while stationed at Fort Meade, Dakota Territory.