Establishment of Diplomatic Relations, 1861.

The United States established diplomatic relations with the Kingdom of Italy in 1861 when it accepted the credentials of Chevalier Joseph Bertinatti as Minister Plenipotentiary of the Kingdom of Italy on April 11, 1861.

Establishment of American Legations in the Italian Peninsula, 1831-48.

Prior to the 1861 unification of Italy, the Italian peninsula was fragmented into several kingdoms, duchies, and city-states. As such, since the early nineteenth century, the United States maintained several legations which served the larger Italian states. In 1831 the United States established a legation to the Two Sicilies at Naples in 1831, while in 1840 the United States established a legation to the Kingdom of Sardinia at Turin. Finally, in 1848, the United States established a legation to the Papal States (later the Pontifical States) in Rome.

Legation of the Kingdom of Sardinia becomes the Legation of the Kingdom of Italy, 1861.

On April 11, 1861, following Italy’s unification, former Minister Plenipotentiary of the Kingdom on Sardinia, Chevalier Joseph Bertinatti, presented his credentials to the United States as Minister Plenipotentiary of the Kingdom of Italy.

U.S. Legation to the Kingdom of Italy moves to Florence and then Rome, 1865-71.

During the period of Italian unification, George P. Marsh, as Minister Plenipotentiary, oversaw the move of the U.S. Legation from Turin to Florence in 1865 and from Florence to Rome in 1871.

Elevation of American Legation to Embassy Status, 1893.

The legation was elevated to an embassy when James J. Van Allen was appointed ambassador on October 23, 1893, though he declined the appointment. Wayne MacVeagh became the first official U.S. Ambassador to Italy when he presented his credentials in Rome on March 11, 1894.

Elevation of the Italian Legation to the Italian Embassy, 1893.

The Italian Legation to the United States became the Italian Embassy to the United States when Rome elevated Minister Baron Saverio de Fava to the rank of Ambassador on June 14, 1893.

Diplomatic Relations Severed, 1941.

Diplomatic relations were severed and the American Embassy in Rome was closed on December 11, 1941, after Italy declared war on the United States.

Diplomatic Relations Re-established, 1944.

Diplomatic relations were reestablished on October 16, 1944, when the Acting Secretary of State announced the decision in a statement released to the press.

American Embassy in Italy Re-opened, 1945.

Ambassador Alexander C. Kirk re-opened the U.S. Embassy in Rome when he presented his credentials on January 8, 1945.

source: U.S. Italy Relations – U.S. State Department, Office of the Historian