President Trump in a 'great mood' as Washington waits for Attorney General William Barr to act on special counsel report: Sources He told those gathered at his Palm Beach retreat he was “glad it's over."

Just after news broke that Special Counsel Robert Mueller had finished his 22 month long investigation into alleged Russian meddling in the 2016 campaign, President Donald Trump appeared to exhale.

The president who was described by sources as being in a “great mood” spent a festive evening dining on the patio at Mar-a-Lago with first lady Melania Trump, the first lady’s parents, and the couple’s son, Barron.

At one point, the family joined by other club members sang “Happy Birthday” to Barron who was celebrating his 13th birthday.

Trump told those gathered at the president’s Palm Beach retreat he was “glad it’s over.”

For the last several weeks, as Washington waited for the special counsel to deliver his final report, sources close to the president have described him as antsy -- constantly asking questions about what the report would look like, how much detail would it provide and whether it would deepen the legal and political challenges facing him and his family.

When the call arrived Friday night that Mueller had handed off his report to Attorney General William Barr – and would not pursue additional indictments -- the questions stopped, the sources told ABC News.

The White House has not been briefed on the contents of the special counsel’s report, according to administration officials.

However, the president, who once described the probe as “a cloud over my head,” told one source he felt the cloud had been lifted.

After dinner, the president addressed supporters briefly at a Republican fundraiser but made no mention of Mueller, according to those present.

Trump later returned to the patio at his Florida country club. He and the first lady sat with Donald Trump Jr. and his girlfriend, former Fox News anchor Kimberly Guilfoyle, as they sipped coffee.

At one point on Friday evening, Trump was briefly praising Attorney General Barr for his leadership, according to a source close the president.

"We feel very prepared for the results. We feel like we're going to be fine,” one administration official told ABC News. “There's a feeling of it is what is it and it's not a very big deal. There isn't an enormous sense of concern. But let's see the facts."

The president had not offered any public reaction in remarks or on Twitter as of early Saturday. Several aides noted his restraint with surprise, especially in regards to his Twitter account. For nearly the last two years, the president has been on an almost daily tirade about the special counsel’s probe calling it a “hoax” and a “witch hunt.”

The president was in Mar-a-Lago for planned meetings with the leaders of various Caribbean nations and was joined on the trip by White House Counsel Pat Cipollone. A late add to the manifest of Air Force One: another White House lawyer, Emmet Flood, who serves as the main lawyer handling issues related to the presidency as it relates to the Mueller investigation.

Sources said the attorneys accompanied the president as a precaution when it appeared possible that Mueller would be concluding his work. As speculation mounted Friday that Mueller would be sending a report to Barr, White House Press Secretary Sarah Sanders quickly raced to join the president on his trip.

In the letter to Congress that Barr submitted Friday, he said he could be sharing the “principal conclusions” of the report with lawmakers as soon as this weekend. Barr arrived at his office at the Department of Justice mid-morning Saturday and sources tell ABC News he is expected to read Mueller’s report for much of the day.

Democrats on Capitol Hill have a conference call led by House Speaker Nancy Pelosi slated for Saturday afternoon to go over strategy on dealing with Mueller’s findings and Barr’s report according to a senior Democratic leadership aide.

With the 2020 campaign already heating up, the Trump re-election team is already preparing their victory lap.

A separate source close to the Trump campaign told ABC News Trump allies may soon take to the airwaves regarding Democrats reaction to the special counsel’s probe. Several had already started field testing a new line of response, saying they had not “seen so many disappointed or sad faces since election night 2016.”

The president spent Saturday golfing at his Palm Beach club. As Trump rode back to his residence, he was greeted by a few dozen supporters waving signs according to a press pool report. One of the signs read: “Trump is better than Reagan.”

On Sunday, he sent a cheery series of tweets including, "Good Morning, Have A Great Day!"