Trump was celebrating passage of the sweeping tax reform he promised to push through if American voters delivered him to the Oval Office.
For this most unconventional of presidents -- impulsive, unpredictable, so often frustrated by the exercise of power -- it was payback time at last.
In the chill December air, under a pale sky dotted with clouds, Trump was celebrating passage of the sweeping tax reform he promised to push through if American voters delivered him to the Oval Office.
The much-anticipated event had been staged with care: lawmakers and advisors, primed to cheer and applaud, surrounded him at the lectern, and packed the majestic staircases that framed the scene.
But the relief was plain to see in Trump's face as the businessman-turned-president -- whose need for recognition appears to know no bounds -- took the stand.
Forgotten, for now, was the bitter failure to repeal Obamacare, his predecessor's flagship health reform.
Forgotten the vicious tweets and jabs pitting the president against members of his own Republican family, who now stood united behind congressional leaders Mitch McConnell and Paul Ryan, slapping each other on the back.
Forgotten the setbacks of recent polls -- chief among them the defeat of Trump's candidate in Alabama, Roy Moore -- which raised the specter of losing Republican control of Congress in the 2018 mid-term elections.
For the 71-year-old president, it was a day for rejoicing, flanked by his daughter Ivanka and son-in-law Jared Kushner -- as well as Gary Cohn, Trump's economic advisor, ex-Goldman Sachs banker and chief architect of the tax reform.
Trump had no speech as such to deliver -- launching instead, with gusto, into a series of off-the-cuff remarks.
He spoke of the "tremendous enthusiasm right now in this country," cracked jokes about the ups and downs of power, how it's "always fun when you win."
"What does it mean? It means jobs, jobs, jobs," he quipped, promising the tax cuts will deliver a shot in the arm for the US economy.
The president dished out smiles, pumped lawmakers' hands -- singled out this "friend" or that "special person."
And the Republicans returned the favor, taking turns to sing his praises.
Setting the tone, House Speaker Paul Ryan credited Trump's "exquisite presidential leadership" for the success of the contentious tax plan, assailed by Democrats as a giveaway to the wealthiest that risks blowing a hole in the national debt
Not to be outdone, Vice President Mike Pence doubled down with a superlative description of Trump's accomplishments -- including a tax cut he dubbed "a middle class miracle."
"President Donald Trump is a man of his word. He's a man of action," said Pence. "President Trump has been making history since the first day of this administration."
For the real estate magnate, elected president with no prior experience of politics, it was a sweet victory indeed.
When Trump first vowed to push through the Republican tax reform before Christmas, it raised amused eyebrows in Washington where many expected it to fall foul of president's inexperience and divisions within his own camp.
But several lawmakers admitted -- in no uncertain terms -- that tax reform was a make-or-break issue for the Republican party ahead of next year's elections.
"This will indeed be a very big day, when people look back at our country," Trump concluded, before heading back to the Oval Office.
Earlier Wednesday Trump had promised a press conference to celebrate the bill's adoption. As it turned out, he took no questions.
The president's team is hoping this could mark a turning point for a leader whose popularity rating lags far below any of his predecessors this early in his term.
But for now, the 45th president of the United States is preparing to spend Christmas break at his Mar-a-Lago golf resort, the "Winter White House," basking in the Florida sunshine and the glow of his first legislative victory.
As for 2018, that is another story.