A Memorial Day weekend tradition in the nation's capital made a whole lot of noise -- all to honor America's veterans and fallen troops.

More than a million motorcyclists and spectators from across the country took part in the non-profit group Rolling Thunder's Ride for Freedom, according to estimates. The ride, past many of Washington's military monuments, also aims to call attention to troops missing in action, and to the struggles of current vets.

It was the 31st such ride, Fox 5 reported. Rolling Thunder's initial goal: to make so much noise that lawmakers couldn't ignore them.

President Trump certainly didn't. "Fantastic to have 400,000 GREAT MEN & WOMEN of Rolling Thunder in D.C. showing their patriotism. They love our Country, they love our Flag, they stand for our National Anthem!" he tweeted.

Rolling Thunder Executive Director Artie Muller told Fox News too many of America's veterans still feel left behind after serving their country. "These men and women have fought for the rights of all of us, so that we can live free the way that we do."

The ride proceeded from the Pentagon to West Potomac Park.

Rolling Thunder aims "to educate the public that many American Prisoners of War were left behind after all previous wars and to help correct the past and to protect the future Veterans from being left behind should they become Prisoners Of War-Missing In Action," according to its mission statement.

Fox News' Garrett Tenney in Washington contributed to this report.

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