The gathering was hosted by C. Boyden Gray, a Washington lawyer who served in top positions in both George Bush’s and George W. Bush’s presidential administrations, and who is known for hosting gatherings of the capital’s Republican elite.
It was a rare night on the town for a president who mostly remains cloistered in the White House when he is in Washington, and who, when he does dine out, usually goes to the steakhouse in the hotel he owns five blocks away.
The evening also highlights the extent to which Mr. Trump has embraced features of Washington politics that he denounced on the campaign trail. He had pledged to “drain the swamp” of the city’s permanent political class and to forsake the contributions of wealthy donors, who he said had too much power.
Mr. Gray could not be reached for comment. Mr. Walsh and Donald Trump Jr. did not respond to requests for comment.
Lindsay Walters, a deputy White House press secretary, stressed that the dinner was not a fund-raiser.
“Tonight the president had dinner with a small group of supporters at the private residence of C. Boyden Gray,” she said on Wednesday night.
Even if no money was collected Wednesday night, the gathering was part of a fund-raising campaign by the two groups that has ramped up in recent weeks with assistance from Mr. Trump, his family and top officials in his administration.
Vice President Mike Pence spoke last month at an America First round table in Dallas, and Donald Trump Jr. has attended events for the groups, as well.
Secretary of Energy Rick Perry spoke Tuesday afternoon at a round table in Houston, which was attended by Mr. Bailey and a number of prominent Texas donors, including the Dallas investor Doug Deason.
“They’re making a pretty serious push,” said Mr. Deason, who is on the finance committee of the America First groups. “It’s an all-out effort to knock it out of the park with this super PAC.”
Mr. Deason explained that the groups are careful not to ask for contributions, or to discuss spending strategies, in the presence of administration officials.
That is because officials are barred by campaign finance rules from coordinating spending strategies with — or raising large sums for — entities like the America First groups, which, unlike campaign and party committees, are not subject to federal contribution limits.
Instead, Mr. Deason said, the administration officials have generally discussed Mr. Trump’s agenda and answered questions from the assembled donors. Mr. Perry, for instance, was asked about the president’s proposed tariffs on steel and aluminum by donors who were concerned about them.
After such events, representatives from the America First groups will follow up with donors to solicit contributions — a common fund-raising strategy for super PACs and other unlimited-money political groups.
Someone with direct knowledge of the America First groups said they had been telling donors that they had already raised $40 million and intended to raise another $60 million for their 2018 efforts.
A majority of the funds raised so far have been collected by America First Policies, a nonprofit group registered under a section of the tax code — 501(c)(4) — that allows it to shield most information about its finances, including the identity of its donors.
America First Action, on the other hand, is required to disclose its donors and expenditures on a periodic basis to the Federal Election Commission.
The group’s most recent report revealed that it raised $4 million last year, with half of that coming from the Los Angeles developer Geoffrey H. Palmer. An additional $1 million came from the Murray Energy Corporation, a coal company based in Ohio that has assiduously courted Mr. Trump as it pressed the new administration to repeal President Barack Obama’s climate change policies intended to shut down old coal-burning power plants.
America First Action spent tens of thousands of dollars at the Trump International Hotel on events for donors, and also paid tens of thousands of dollars each to firms associated with Mr. Trump’s first campaign manager, Corey Lewandowski, and his newly named re-election campaign manager, Brad Parscale, among other loyalists.