“The vice president’s family didn’t have Secret Service back then,” Ford Bales says. “I had Secret Service before my mother did.”

(The Ford family never resided at Number One Observatory Circle, because it was in the process of being transformed into the official residence for the vice president at the time; until 1977, the second-highest-ranking member of the Federal government lived in his private home.)

When President Richard M. Nixon resigned on August 9, 1974, following the Watergate scandal, Susan’s unassuming dad became the first man to hold the offices of vice president and president without having been elected to either. As a transition team cleared out Nixon’s stuff from the White House, cameras captured the new leader of the free world as he picked up the morning paper from the front step of his suburban home.

Susan liked life in the White House, partly because, after having been raised in a crowded house when she wasn’t living in a dorm, it was the first time she had ever had a bathroom to herself.

In the fall of the 1974-1975 school year, not long after the new president had told the country, as part of his barebones inaugural address, “Our long national nightmare is over,” one of Susan’s classmates, Gail Frawley (now Granowitz), had an idea. “We were having our prom meeting, and I said, ‘Why don’t we have the prom at the White House? Let’s ask Susan if it would be O.K.,’ ” she says.

Susan sought the approval of the White House chief usher, Rex Scouten, who was in charge of official functions, as well as the permission of her parents. “They said, ‘Yeah, as long as you pay the expenses, so it’s at no cost to the Federal government,’ ” Ford Bales recalls. “That’s what I remember.”

At Holton-Arms, Ford Bales was, in her words, “a B, C student.” She liked horseback riding, needlepoint, tennis, skiing, and photography. “In those days, you were cool, to have a camera hanging off your hip,” she says.

The only one of the four Ford children young enough to reside full time at the White House, she added freshness to Washington life in the aftermath of the dour Nixon years. The press found it amusing when she barged into the Oval Office to ask her father for her allowance, and she was photographed with Shan, her Siamese cat; and, again, in gym shorts and sunglasses, while washing her car on the White House driveway.

“Susan was very popular, and her social life was very important to her,” says Sally Alexander, who was head of the Holton-Arms English department in 1975. She adds that it was complicated for Susan, after she had made the transition from a relatively anonymous congressman’s daughter to someone in need of a security detail. “Her Secret Service men used to hang out in my office,” Alexander says. “I asked one of them one time, ‘When Susan goes on a date, how close do you have to be?’ He said, ‘Sally, our job is to protect Susan from outside danger, not to protect her from herself.’ ”

Her new status attracted unwanted attention from a fellow student on one occasion, Alexander recalls. “I remember one of our middle-school girls started writing Susan notes. It was as if Susan had ceased to be a senior at Holton and had become a princess. ‘Oh, maybe Susan will advise me about things that make me unhappy.’ The Secret Service had to get into that. Things like that were hard for Susan. She just wanted to be herself.”

But her new circumstances played to her advantage when it came to the site of the Holton-Arms prom.