Charles also heralded the alliance when he followed in the footsteps of his late mother, Queen Elizabeth II, and became the second British monarch to address Congress.

Recognizing the 250th anniversary of American independence, Charles said: "From the bitter divisions of 250 years ago, we forged a friendship that has grown into one of the most consequential alliances in human history."

But he also split from Trump in key areas by showcasing an unyielding support of NATO and urging the rejection of isolationism.

Still, all parties have praised the trip, and Trump—a long-time admirer of the royal family—showcased great affection for Charles when he hosted a state banquet in honor of the royal visit.

Charles and Camilla also spent time in New York, where they joined local officials including NYC mayor Zohran Mamdani at a wreath-laying ceremony to commemorate the lives lost on 9/11.

And the royal couple stopped in Virginia to honor fallen service members at the Arlington National Cemetery. They also attended a block party celebration in Front Royal, a small town in Virginia, to celebrate America's 250th "birthday."