Obama Family Farewell Includes a Final Missive to Donald Trump

— -- The Obama family exited the east side of the U.S. Capitol building this afternoon after Donald Trump’s inauguration, heading first by helicopter to Joint Base Andrews in Maryland, where they boarded Air Force One bound for Palm Springs, California.

After leaving a written letter for his successor, Donald Trump, on the Resolute Desk, President Obama left the Oval Office for the last time this morning and walked down the White House Colonnade.

“Are you feeling nostalgic?” a reporter shouted along the way.

“Of course,” Obama replied.

“Any final words for the American people?” Obama was asked.

“Thank you,” he said.

The Obamas this morning also welcomed the future first family, the Trumps, to the White House for tea before departing together in the presidential motorcade for the inauguration ceremony. Two by two, Michelle Obama and Melania Trump, Joe Biden and Mike Pence, and Barack Obama and Donald Trump, walked through the White House doors for the 11-minute drive down Pennsylvania Avenue to the Capitol.

After the Capitol ceremony, Barack and Michelle Obama said goodbye to the Trumps and took off in Marine One for Joint Base Andrews. But before the helicopter left Washington, it flew over the White House where Obama could take another look at the residence.

Inside an airplane hangar at Joint Base Andrews, President Obama delivered remarks to his staff at a farewell event where he offered words of encouragement.

"This is just a little pit stop. This is not a period, this is a comma in the continuing story of building America," Barack Obama said. "It wasn't blind optimism that drove you to do all this work. It wasn't naivety. It wasn't willful ignorance to all the challenges that America faces. It was hope in the face of difficulty. Hope in the face of uncertainty. You proved the power of hope."

The Obamas shook hands with staffers before climbing the steps of the presidential plane to wave goodbye.

The plane, with a call sign for the flight of "Special Air Mission 28000" rather than Air Force One, departed at 1:40 p.m. ET for California.

Meanwhile, former Vice President Joe Biden and his wife, Jill, this afternoon departed via train to Wilmington, Delaware. "Hey guys, back on Amtrak," Biden said as he boarded.

As for the Obamas, White House press secretary Josh Earnest told reporters they were looking forward to leaving town to “relax a little bit.”

“The president vowed to take his family to a destination that is warmer than Washington, D.C., on Friday and Palm Springs fits the bill,” Earnest said Tuesday.

“This is a community that the president has visited on a number of occasions as president of the United States. He and his family have enjoyed the time they've spent there in the past. And they're looking to travel there on Friday, looking forward to traveling there on Friday.”

The Obama family will be returning to Washington, D.C., where they will live at least until daughter Sasha graduates from high school.

Before their departure from the White House today, staffers there presented the president and first lady with two U.S. flags that flew over the "The People's House" on the first and last day of his presidency.

ABC News’ Alex Mallin and Josh Haskell contributed to this report.