Disney Celebrates America live updates: DC's Reagan Airport closes for fireworks, flyovers

Britain’s King Charles is congratulating President Donald Trump and the American people on the 250th anniversary of U.S. independence, writing in a statement, "This year marks a truly historic milestone and a moment of great celebration for Americans everywhere."

The monarch praised the relationship between the two nations as "one of extraordinary evolution, from overcoming conflict to forging one of the closest and most productive alliances the world has seen."

"The connection between our peoples is one that I trust will only grow stronger with time," he wrote. "As you mark this momentous occasion, my wife and I send our warmest good wishes to you and to the people of the United States of America, today and in the years ahead."

-ABC News' Claire Bower

1:49

July 4th by the numbers: America 250How America is celebrating by the numbers.

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56: The number of people who signed the Declaration of Independence.

13: The number of times the descendants of the Declaration of Independence signers tap the Liberty Bell to recognize the original 13 colonies.

2276: The year that a time capsule buried in 2026 will be reopened. Mementos from across the country will be inside, including Mardi Gras beads from Louisiana, a whale bone from Maine and a crystal from New York City’s New Year’s Eve ball.

17,000: The estimated number of professional fireworks displays round the country.

7:11

The enslaved people who built America"GMA" shares an exclusive report from ABC News in collaboration with the 10 Million Names Project on the hidden history of the White House and a historic genealogical breakthrough.

ABCNews.com

In a breakthrough discovery, ABC News and American Ancestors, one of the nation's largest genealogical organizations, found the first confirmed living descendants of an enslaved individual who helped build the White House.

"Good Morning America" co-anchor Robin Roberts spoke exclusively with Jackie Smith Sullivan and her daughter Ashley Swain as they learned Swain's fourth great-grandfather, Calvert Ambush, helped build the North Portico of the White House in the summer of 1829.

"There's a piece of him that's inside of me,” Swain said. "To understand whose blood is running through my veins, understand the connection that I have and how we got to where we are today, I think that is amazing."

Click here to read more.

America's Independence Day Parade, which was scheduled for 10:30 a.m. on July 4 in downtown Washington, D.C., was canceled by organizers late Friday due to the dangerous heat.

"The National Weather Service has an Extreme Heat Warning for the District of Columbia, with heat index values expected to reach between 110°F and 115°F," a statement on the website said. "This decision was made after extensive consultation with the National Park Service, the District of Columbia City Government, and Freedom 250, and careful consideration of the safety of our participants, spectators, and staff as the top priority."