An hour before midnight on the Fourth of July, President Trump appeared on the National Mall to give a speech that blended American history, tales of old war heroes, happy patriotic talk and a handful of political chum.

As he did one night earlier at Mount Rushmore, Mr. Trump used the nation’s birthday to scaremonger about Democrats four months before the midterms (he talked a lot again about “communism”) and demand that Congress pass an act that would make it harder to vote.

While extolling the values that make this country special, he said: “Unlike so many others in the world, in this country we have freedom of speech, freedom of religion, equal justice under the law — although I wasn’t treated that well, but we won’t get into that.”

What was meant to be the centerpiece of the nation’s 250th anniversary celebration was in some ways just another Trump rally. The president who calls himself “the man who gets much larger audiences than Elvis in his prime” has a set list. He rarely deviates from it.

Even the warm-up acts were the same as usual. Mr. Trump got the tenor Christopher Macchio to sing “God Bless America.” Next up was Lee Greenwood. He sang “God Bless the USA.”

These were the singers the organizers could get after many other entertainers bolted, wanting nothing to do with the lawn parties that the Trump administration had planned for the nation’s anniversary.

It was a minor miracle the speech happened at all.

Days of extreme heat in Washington led to rolling storms and lightning bolts Saturday night. People who traveled from all over the country to stand in line for hours were forced off the mall by the authorities and told to take cover in government buildings shortly before the president was meant to appear.

A few minutes after 9 p.m., he posted online that the show would go on, even if it meant he had to speak at 2 in the morning. “Storms bring luck to whatever the occasion,” he wrote. “They also make events a little bit more exciting!”

About an hour later, he posted again: “I’M HERE!!!”

About an hour after that, he walked onstage.

“I want to thank everybody, because they did the right thing,” he said. “I said, ‘There’s no way, if we have to speak in front of one person at 4 o’clock in the morning, I’m going to be there!’ There’s no way we can be deterred.”

He brought artifacts with him.

There was a flag he said was the first to fly over the Brooklyn Bridge. There was a flag that, he said, “flew triumphant when the British waved the white flag of surrender at Yorktown.”

The speech did contain much more history than what one ordinarily hears at a Trump rally. The president talked about the “genius” of the founding fathers. He made mention of Annie Oakley, Buffalo Bill and Lewis and Clark. He told the story of Sgt. William Harvey Carney, the first African American man to win the Medal of Honor. “He loved our country,” Mr. Trump said, “he loved our flag.” Several veterans appeared onstage, and Mr. Trump told stories of their valor and thanked them for their service.

But his typical asides had a way of puncturing the history lesson.

“We rebuilt our military in my first term,” he said at one point. “We used it a little bit in our — actually, I should say third term, but I won’t do that, because I don’t want any controversy.”

After about 40 minutes, he was finished (sometimes he goes for double that).

“We have a great fireworks display tonight, and I’m going to be watching it with you,” he told the crowd who’d braved the heat and the rain and the lightning to hear him.

“It’s going to start very quickly, so, thank you very much,” he said. “You’re going to really like this.”