() A celebration honoring the U.S. Army kicks off in Washington this week, giving the public a chance to learn about the Army, interact with soldiers, and see up close the equipment they use to defend the nation.

Army officials estimate around 200,000 people will attend the highly anticipated parade on Saturday, which is also Flag Day and President Donald Trump’s 79th birthday.

The Army is turning 250 years old. It was officially established on June 14, 1775 more than a year before the Declaration of Independence. It remains the largest branch of the U.S. military with more than 1.2 million people worldwide.

“We have such a rich history and heritage from the Revolutionary War, WWI, WWII, Vietnam, the global war on terror,” said Col. Kamil Sztalkoper, director of public affairs for the III Armored Corps at Fort Cavazos in Texas. “There are so many stories of our soldiers, their performance in combat, their heroism that just needs to be told.”

Fort Cavazos is providing 90 of the 150 military vehicles featured in the parade. Those include 28 M1A2 Abrams tanks, 28 Bradley Fighting Vehicles, 28 Strykers and six Paladin howitzers.

Arguably the most lethal of the bunch, Sztalkoper described, is the Abrams tank with a 120mm main gun, a 50-caliber machine gun, and a 7.62mm coax machine gun. It seats a four-person crew: the driver, gun loader, gunner and tank commander.

Sztalkoper said the process of preparing the vehicles was the same as deploying them for training or war. Soldiers checked fuel levels, replaced track pads, and touched up paint. They loaded the vehicles onto 51 rail cars pulled by two locomotives. The train left Fort Cavazos on June 2 and landed in Jessup, Md., on June 7.

On Wednesday, the Army will move the vehicles to West Potomac Park, where people can view them until the parade. Later that evening, people can watch a live military performance by the Army’s Twilight Tattoo at Joint Base Meyer-Henderson Hall, Summerall Field.

On Thursday, the media will preview aircraft participating in the parade, including the UH-60 Black Hawk, AH-64 Apache, and CH-47 Chinook. An Army Birthday Run/Walk is set for Friday at Joint Base Meyer-Henderson Hall.

The big day on Saturday starts with a wreath-laying ceremony at the Tomb of the Unknown Soldier in Arlington National Cemetery. The festival at the National Mall begins at 11 a.m. ET, offering a chance to interact with soldiers and some of the equipment they use, like enhanced night vision goggles and drones.

The parade starts at 6:30 p.m. and will last for about an hour. It’ll happen on Constitution Ave. NW between 15th St. and 23rd St., starting on 23rd St. NW. Following is a concert at the Ellipse and fireworks at 9:45 p.m.

In addition to the pomp and circumstance, a “No Kings” protest is taking place across the country on Saturday. Over a hundred organizations are coordinating the effort, with more than 1,500 events planned. Notably, none are in Washington.

Lisa Gilbert with Public Citizen said the goal isn’t to oppose the military but to send a strong message to Trump.

“People are talking about the ways in which his administration has gone too far, defying the courts, deporting people … attacking civil rights, slashing services. All of that is happening under his watch because he thinks he has absolute power. We just want to be loud as we can, saying enough is enough,” Gilbert said.

There are No Kings events planned in the surrounding Washington suburbs. A flagship march is scheduled in Philadelphia from 12 p.m. to 3 p.m. at Love Park.