A replica of the French warship that carried the Marquis de Lafayette to help American revolutionaries in the war of independence crosses the Atlantic, heading for the US.
Thousands of people bid farewell on Saturday at Ile d'Aix in France to see off the replica ship Hermione.
Before the ship's departure, French President Francois Holland visited the replica vessel, which cost €25m (£18m) to build.
"The Hermione is a glorious page of our history… thus was sealed one of the finest alliances, a fraternal alliance," he said.
The US consul in Bordeaux, Thomas Wolf, read out a statement from President Barack Obama, honouring the "unwavering friendship and solidarity between the two countries".
"The tribute we are paying today to the extraordinary efforts by General Lafayette and the French people in favour of the American Revolution reminds us that our partnership with France has made it the oldest ally of our nation," he said.
Around 80 volunteer crew members will sail the 65m ship to Boston made by the French general who helped revolutionaries fight for an independent US.
The crew plans to make landfall on 5 June in Yorktown in Virginia, where US troops led by George Washington and French soldiers accompanied by General Lafayette led a victory against the British in 1781.
The frigate will take a two-month tour of important sites of the American Revolution, including Annapolis, Boston, Philadelphia and New York City.
Both the historical and the modern ship were built in the same shipyard, in Rochefort in southwest France, although the original Hermione was constructed in just six months in 1778.
The replica took nearly 20 years to design and build, and is to make a first stop in the Canary Islands on its way to the eastern coast of the US. Hermione will also sail into New York Harbour just in time for 4 July independence celebrations
"If it hadn't been for that French intervention at that time, the war of independence probably wouldn't have been won." Said Miles Young, president of the Friends of Hermione-Lafayette in America.