The Prince of Wales said during his acceptance speech that he realised he had been coming to the US for the past 40 years.
"Look what it's done to me," he joked before saying his only anxiety about the evening was "that I might quite possibly send my wife to sleep during my speech."
Prince Charles has been awarded the Teddy Roosevelt International Conservation Award for his "extraordinary" conservation leadership.
The Prince of Wales accepted the award as he attended the International Conservation Caucus Foundation dinner.
Barack Obama told Prince Charles that American people rate UK royalty above their own politicians on the royal couple's Washington tour.Read the full story ›
Watch Prince Charles try - and fail - to get a strike on the bowling alley during a trip to a veterans' retirement home in Washington.Read the full story ›
Charles and Camilla spent a busy first full day of their US trip visiting memorials to President Abraham Lincoln and Martin Luther King Jnr.Read the full story ›
Prince Charles attended a reception at the British Ambassador to the US's residence in Washington after a busy day of events across the city.
Prince Charles used his trip to Washington to make an impassioned plea for action to end the dumping of plastics in the world's oceans.Read the full story ›
The Prince of Wales and the Duchess of Cambridge began their four-day trip to the USA by visiting some of Washington's famous monuments.
However, many in the crowds weren't entirely sure who the heir to the throne was and those who did were disappointed the couple weren't William and Kate.
ITV News correspondent Tim Ewart reports from Washington:
British Ambassador to the US Sir Peter Westmacott said he is "delighted" to welcome Prince Charles and the Duchess of Cornwall back to Washington after 10 years.
The royal couple attended an event at the British Embassy in Washington.
Prince Charles and the Duchess of Cornwall have arrived at the British Embassy in Washington for an event marking the beginning of their four-day visit to the US.