A U.S. Marine greets a visitor, his head lowered to avoid the dust unsettled by the departure of Marine One. Without the caption, the Marine seems to be holding his head in quiet reverence to the metal bird. The enlarged color photo parallels the service of Diana Walker, who served as a White House photographer for Time magazine for two decades, quietly capturing the private moments of the presidency.

“Oh yeah, I was nervous,” recalls Walker of her first time photographing the White House for Washington Monthly. “I didn’t have a clue. I just followed everybody else — they went out the door, I went out the door, they tried to be the first out the door, I tried to be the first out the door.”

“Diana Walker Photojournalist” is the newest exhibit at the Smithsonian’s National Museum of American History and features 135 black-and-white and color photographs spanning five presidential administrations from Gerald Ford to Bill Clinton, as well as a number of magazine covers and enlarged photos. The exhibit will continue through Jan. 4, 2004, in the Taylor Gallery by the Constitution Avenue entrance. At the close of the exhibit, the photographs will be added to the museum’s photographic history collection.

The exhibit is painfully simple with plain gray walls, modest lighting and greenery adorning the corners. Yet the display is effective in not only revealing the private moments and public celebrations of five presidents and their families, but documenting Walker’s professional career, which did not begin until her 30s.

“I am terribly pleased with [the exhibit],” Walker said. “You can look at plans for a show and talk about it, but not until it’s mounted, lit, and fixed — it’s not until then that you get the impact of it.”

After working in the retail dress business with her mother for 10 years, Walker said she “came to the realization that I wanted to do something more.”

Walker picked up her first camera, a Kodak Pony 135, in the sixth grade, and had pursued photography as a hobby ever since. With the encouragement of a good friend, Walker took up photography professionally and created a business called “I am a Camera” where she did weddings, bar mitzvahs and book jackets — “anything people would ask us to do,” Walker said.

And then Charlie Peters called.

“I did [I am a Camera] until Charlie Peters, the editor of the Washington Monthly, called me up and said, ‘How would you like to work for me?’” Walker said. “‘But Charlie,’ I said, ‘your magazine doesn’t have any pictures!’”

“And he said ‘Well, I want some. I don’t have any money for you, none, but I’ll give you 25 dollars for each picture, I’ll arrange to get your credentials at the White House and on the Hill, and you can freelance all you want.’ And I said, ‘You’re on.’”

From there, she freelanced for the Village Voice, Business Week and Fortune Magazine before signing on with Time Magazine in 1979.

“They offered me a contract, put me on the masthead, and I’ve been there ever since,” Walker said.

Michelle Delaney, the exhibition curator of the American History Museum, contacted Walker with the idea to display her work. After looking at hundreds of photos at the Walker residence, Delaney was able to narrow her prospects to 300 photos. One-hundred-thirty-five photos made the final cut and included images of President Jimmy Carter praying at the National Cathedral for the return of U.S. citizens taken hostage in Iran in 1979, mourners entering the funeral of Japanese Emperor Hirohito in Tokyo in 1989, and Rosalynn Carter playing basketball with the Harlem Globetrotters.

The exhibit is grouped in categories with titles such as “Presidents in Private,” “Clinton’s Last Week,” “Travels with the Presidents” and “First Ladies.” Accompanying presidents, first ladies and celebrities are Walker’s thoughts, placed next to captions in bold text.

“Shooting with next to no light at a negligible shutter speed, I had the thrilling feeling of capturing a moment — if, of course, I’d done all the technical things right. One never knows,” thought Walker as she captured a sentimental Clinton moment as the president draped his arms around Hillary Rodham Clinton’s shoulders.

“Although we wanted a heavy presence of the presidents, we wanted to show that she had a dual career,” Delaney said.

As a result, photos from outside of the political spectrum are present and grouped with titles such as “Beyond Political Photography” and “Portraits.”

It’s difficult for Walker to pick a favorite photograph because “I’ve lived with these pictures for a long time … I have a really hard time deciding which is my favorite because I come from it from such a different view.”

But she still can’t help but pick out two for their humor: one with former President Ronald Reagan laughing while England’s Queen Elizabeth cracks a joke at an event, and a black-and-white photo of then-Secretary of State William Cohen, former President Bill Clinton, former Secretary of State Madeleine Albright and Sandy Berger lined up in a row.

“We were all making comments we shouldn’t have about how the [NAFTA] meeting was getting very boring,” Clinton said of the photo in Walker’s book, “Public & Private: Twenty Years Photographing the Presidency.” “So finally we decided we had to make like the monkey. Cohen started this hear no evil, and then I was next so I spoke no evil, then Madeleine saw no evil, so Sandy Berger said, ‘I’m evil.’”

Although Walker said she enjoyed her time at the White House, she retired after covering both Clinton administrations.

“Frankly, I was tired,” she said. “And I wanted to see if I could have another life that was not controlled so entirely by the movements of the president.”

She still photographs professionally — she recently did a portrait of Albright and Sen. Clinton (D-N.Y.) — but describes her assignments as “special things that my editors think I would be suited for.”

A current project is photographing actress Anna Deavere Smith for a one-woman show.

What still amazes Walker is how “we are out there shooting these pictures and in some miraculous way, it is put on a page in a magazine … this exhibit shows just that.

“It’s kind of strange to look at all the places you’ve been and all the things you’ve seen hung up in an interesting way,” she said.