1849 was a banner year for Pius IX. Chased out temporarily from the Papal States that year due to a revolution, he also became the first pope to set foot on US soil. On June 7, 1849, the USS Constitution under Captain John Gwinn made a port call at Naples. All of Italy was up in arms, revolutions raging throughout the peninsula and not just in the Papal States. Throw in the Austrians and the French, and there was a great deal of politics and war for the Americans in the Mediterranean to worry about. The USS Constitution was in Naples to make the point that American neutrals would be protected. The commander of the American Mediterranean Squadron, Commodore Charles W. Morgan, arrived at Naples on July 25 in the ultra modern side steam frigate USS Mississippi. He vetoed a proposal of US diplomats that the Constitution sail to Gaeta for a visit of the ship by the Pope and King Ferdinand II of Naples. The US wished to stay neutral in the conflict between the Pope and King Ferdinand and the revolutionaries they were facing. Instead, he ordered the Constitution to sail to Messina, Sardinia and then Northern Italy, to protect US neutrals in these locations. He then steamed for Tunis.
On July 30, the US Charge John Rowan paid a courtesy call, along with the ship’s surgeon of the Constitution, on King Ferdinand to congratulate him on the birth of a child by his queen. During the meeting he extended an invitation to the King to visit the Constitution. It is unclear whether at this time he was aware of Commodore Morgan’s order against such a visit. Captain Gwinn, apparently deciding to follow the instructions of Rowan rather than the orders of Morgan, sailed for Gaeta with Rowan on board on July 31 and arrived there early on August 1. Going on to Rome, Rowan extended an invitation to Pius on August 1 to visit the Constitution.