The permanent care and feeding of the President of the United States is an industry staffed by hundreds of people, largely supported by taxpayers, and little understood beyond the gates of 1600 Pennsylvania Avenue. First families move in and out—"They get a four- or eight-year lease," says Gary Walters, former chief usher of the Executive Mansion. But the staff, customs, and mechanics surrounding the world's most powerful chief executive endure, often for generations.

Walters knows this well. As a deputy manager and then manager of the most famous address in the U.S. for 31 years, from Gerald Ford to the second President Bush, Walters spanned six presidencies and crises both global and domestic until his retirement in 2007. He ran a house with a 90-member residence staff of butlers, maids, chefs, maître d's, elevator operators, florists, curators, carpenters, electricians, and plumbers. In some ways it was like running the world's most exclusive hotel, except that Walters was in charge of a building with four major and often conflicting functions: home, office, grand museum, ultimate event site. Incredibly, the White House has welcomed up to 30,000 guests in a single week.

Walters, an Army veteran and a former officer in the old Executive Protective Service (now known as the Secret Service Uniformed Division), brought military precision and the utmost discretion to a job that was never 9 to 5. His worst times, he recalls, were when one first family moved out, typically around 10 a.m. on January 20, and the other moved in—by 4 p.m. the same day.

Walters's goal was to have the departing family's possessions out and the new socks in dresser drawers, personal furniture arranged, pictures hung, family photos displayed, favorite snacks in the kitchen—all in that six-hour time frame. There is no chance to get a head start, since the new President does not officially take office until January 20 at noon, two hours after his moving van pulls up under escort in the White House driveway as the outgoing President leaves for the Capitol. To make the deadline, Walters would deploy the entire 90-member staff at once, divided into teams with specific tasks. Months of planning included repeat verbal dry runs. (No such rehearsals took place before Richard Nixon's early departure, however. Word went out that the First Lady had made a request through the usher's office for packing boxes. "That's how we knew," said Betty C. Monkman, a former White House curator.)