Scenes of Trump’s Fourth of July Celebration

Thousands of people braved scorching, humid weather as they poured into Washington for Fourth of July festivities on Thursday, celebrating the nation’s birthday among the monuments and memorials to its history.

But this year’s celebration also promised to be stamped with President Trump’s personal brand. JumboTron screens were ready to display his remarks for the crowd in the evening. And tanks and other fighting vehicles stood on display, even if few people could clearly see them.

A divided crowd descends on the Mall.

Inside the secure area near the Lincoln Memorial, where Mr. Trump plans to hold his “Salute to America,” several thousand people — many wearing “Make America Great Again” hats and decked in red, white and blue — had camped out several hours ahead of the president’s speech.

One woman wore a “I’m a Trump Deplorable” T-shirt, followed not far behind by a man in a “Veterans for Trump” shirt. A man wearing a shirt that said “Vote Democrat: Make America a Third World Country” walked through the crowd yelling about the end of the democracy. A lone Trump opponent walked quietly with a sign that said “Dump Trump.”

Outside of the secure area, on the other end of the National Mall, where PBS will be holding its annual Fourth of July concert — a separate event from the president’s rally — there appeared to be far fewer Trump supporters. The president’s red MAGA hats were hard to find, and Trump 2020 T-shirts were nowhere to be found.

Storms threaten the festivities.

Anyone who has lived in Washington knows what the weather is like on a typical July day. This day turned out not to be any different: steamy and hot in the morning, followed by periods of storms.

Around 3:30 p.m., crowds sought shelter as rain rolled in. And forecasts suggested a continuing chance of thunderstorms in the evening, when Mr. Trump is to take the stage in front of the Lincoln Memorial.

If low clouds or high winds force the Pentagon to call off the flyovers by the military aircraft, that would leave the president with a soggy speech devoid of the dramatic moments he so craves.

A military display, with a few hitches.

It’s hard not to be impressed by the military might of the United States armed forces, and organizers were trying to assemble a display to match.

For those on the ground, the main attractions were supposed to be the two M1A2 Abrams tanks, not far from the Lincoln Memorial, and the M2A3 Bradley Infantry Fighting Vehicles in front of the presidential stage. But if the president’s supporters were hoping to catch a glimpse of them, they were disappointed. The vehicles appeared to be inside the V.I.P. section behind a chain-link fence.

In the air, fighter jets will include the F-35 stealth fighter and the Navy’s Blue Angels, who will perform in the sky. And one of the Boeing VC-25s that usually serve as the presidential aircraft is set to roar over the National Mall.

Mr. Trump’s speech is also set to include military leaders, though not everyone he requested will be there. The Pentagon was given only a few days’ notice that Trump wanted by his side all the Joint Chiefs of Staff and all the service secretaries.

Most of the Joint Chiefs were on leave or on travel. Gen. Joseph L. Lengyel of the Air Force, the head of the National Guard Bureau, had a long-scheduled trip to the Middle East that was on, then off, then on again as of Wednesday. Another National Guard general was tapped to attend.

Of the other chiefs, only Adm. Karl Schultz, the Coast Guard commandant, is joining Gen. Joseph F. Dunford Jr., the Joint Chiefs. The others are on travel or on leave, and are sending deputies in their stead.

Will Trump’s speech stick to script?

White House officials say President Trump plans a nonpolitical speech that honors the American military and celebrates — on behalf of everyone — the country’s 243rd birthday. He is scheduled to speak for about 20 minutes, interrupted by dramatic flyovers of military aircraft and one of the planes that serve as Air Force One.

But Mr. Trump is hardly known for sticking to the script at his “Make America Great Again” rallies, and he rarely talks for only 20 minutes. Will he treat his Fourth of July address differently? Or will the celebration of Independence Day become a celebration of the Trump administration, filled with the usual boasts and grievances that are becoming the centerpieces of his re-election campaign?

Only his speechwriters know — and even they may be surprised in the end.

Away from the president, longtime staples of the holiday proceed.

President Trump has a way of drawing attention from everything else. But three other unrelated Fourth of July events are taking place in the nation’s capital on Thursday.

The traditional parade proceeded down Constitution Avenue several hours before Mr. Trump’s arrival. It consisted of marching bands, floats, giant balloons, drill teams and military units.

At the west lawn in front of the Capitol, PBS will present “A Capitol Fourth,” a concert that has taken place for years, at 8 p.m. Organizers went out of their way to say that their event had nothing to do with the president’s rally at the other end of the Washington Mall, about two miles down the road.

After the concert, fireworks will explode above the Washington Monument, well after Mr. Trump’s event is over.

A question of crowd size.

President Trump loves his crowds.

That was clear after he complained about the reporting that his inauguration crowds were not, in fact, the largest ever. And it’s clear every time he brags about the size of his crowds at rallies around the country.

So pay close attention to the size of the crowd that assembles to watch him deliver his speech. If reporting suggests it is small, Mr. Trump may tweet.

Also keep an eye on the composition of the crowd. Organizers are expecting many Trump supporters wearing the president’s trademark “Make America Great Again” hats. But they are also bracing for the possibility of clashes between Trump supporters and protesters who have already said they will assemble Thursday as well.