(CNN) With jets roaring overhead and a poncho-clad crowd before him, President Donald Trump implored Americans to come together Thursday in a show of national pride -- a rare unifying message from a deeply divisive President that came after days of controversy and criticism over his precedent-shattering military spectacle on the National Mall.

"We must go forward as a nation with that same unity of purpose," Trump said, filmed through rain-streaked bulletproof glass as showers beat steadily on his audience. "As long as we stay true to our course, as long as we remember our great history, as long as we never, ever stop fighting for a better future, then there will be nothing that America cannot do."

After a flyover from the plane that normally serves as Air Force One, Trump delivered 20 minutes of remarks that were an homage to the nation's early history and its military. But he also spoke about more recent advancements in civil rights and gender equality. And he looked ahead, declaring the American flag would soon be planted on Mars.

Ahead of his speech, Trump's skeptics wondered if the notoriously unpredictable President would remain apolitical. And White House aides scrambled to distribute tickets, worrying about Trump's reaction if the crowd appeared thin.

But by Thursday evening, a soggy mass of onlookers -- many wearing red "Make America Great Again" hats -- had assembled near the Lincoln Memorial to hear the President deliver what was ultimately a message of national pride.

"As we gather this evening in the joy of freedom, we remember that we all share a truly extraordinary heritage," Trump said in remarks that did not veer off-script. "Together, we are part of one of the greatest stories ever told — the story of America."

In a crowd-pleasing closer, Trump hailed each branch of the military as aircraft from their fleets -- -- including a B-2 stealth bomber and the Blue Angels -- sailed overhead, causing Washington's buildings to shake and rumble. Bands heralded the individual branches with their official march songs. M1 Abrams tanks transported by heavy rail sat on display.

Trump's plans were a sharp change from how the holiday has been marked in the nation's capital by previous presidents from either party.

The spectacle was likely to delight many Americans who view the military as one remaining unifying force for pride in a country divided along political, racial and economic lines. But it's also drawn skepticism and criticism for its costs and political hue.

There were to be about 750 to 800 military personnel taking part in the celebration, a defense official told CNN. That didn't include the 900 hundred members of the DC National Guard who were activated to provide traffic control and security on the streets and in the subway system.

Trump was hoping for an enormous crowd, and July Fourth reliably draws plenty of people to Washington. But the last time he delivered an address on the National Mall, on Inauguration Day, he was disappointed by the turnout, or at least in the way the turnout was depicted on the news

That left some of his aides working overtime to fill out the space along the Mall where he spoke. Some people who were offered tickets this week -- including donors and administration officials -- said they'd already made other plans.

Trump addressed the masses in front of Abraham Lincoln's 19-foot marble likeness, framed by the iconic Doric columns of the 16th President's memorial. On television, however, his face was partially obscured by rain streaks on the clear barrier constructed to protect him.

It's all a vastly scaled-up version of how presidents ordinarily celebrate July Fourth , the date American colonists officially served notice to Britain in 1776. Usually the holiday is marked with a picnic for service members and their families on the White House South Lawn, followed by a viewing of fireworks over the Washington Monument.

Presidents haven't traditionally delivered public remarks, much less an address on the National Mall. And the day hasn't been marked by such overtly militaristic displays.

That caused concern even among US military brass that their ranks could end up politicized, according to people familiar with the matter. In the planning for the event, Pentagon leaders had reservations about putting tanks or other armored vehicles on display, a source with direct knowledge of the situation said.

As the final details came together, several top military chiefs of the individual services did not attend and instead sent alternates, though some said they had prior plans.

The military displays Trump ordered up -- which included the flyovers, tanks and other ceremonial units such as the Old Guard Fife and Drum Corps, the US Army Band ("Pershing's Own") and the US Marine Corps Silent Drill Team -- led some to compare the event to the authoritarian parades seen in places like China or North Korea.

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But Trump's inspiration was actually a parade in France, which he witnessed with delight on Bastille Day in 2017. He immediately began formulating plans to stage a parade of his own, though cost estimates later caused him to reduce his aspirations to the speech and military pageant seen Thursday.

Through it all, Trump took enormous interest in even the smallest details, from the staging to the military equipment on display.

It's those details that were likely to ratchet up the costs of the event, though the massive fireworks display that will cap the evening has been donated.

, according to The Washington Post, money that the paper says is usually "primarily intended to improve parks across the country." Already, the National Park Service has redirected nearly $2.5 million to help cover costs related to the July 4 extravaganzaaccording to The Washington Post, money that the paper says is usually "primarily intended to improve parks across the country."

It's not clear how much the event will cost altogether, though Trump attempted to downplay the amount on Wednesday.

"The cost of our great Salute to America tomorrow will be very little compared to what it is worth," he wrote on Twitter. "We own the planes, we have the pilots, the airport is right next door (Andrews), all we need is the fuel. We own the tanks and all. Fireworks are donated by two of the greats. Nice!"

That wasn't entirely truthful -- the planes used in the flyovers came from California, Missouri, Kentucky and Florida. And the costs of the event extend well beyond the military equipment.

For example, just the "transparent ballistic armor" used to protect the President during his speech could cost more than $24,000, according to government records

This story has been updated with additional developments Thursday.