Can there be any doubt that, when the gates close and the last visitor leaves this historic burial ground, band leader John Philip Sousa reaches for his baton, Civil War photographer Mathew Brady tweaks his camera, and J. Edgar Hoover tries to keep the whole mess under control?

This is Congressional Cemetery, where Washington's political and social establishment rests in eternal peace. In the 1800s, its heyday, this was the site of grand funeral processions. Tens of thousands of Washingtonians would gather to watch soldiers carry fallen leaders down a slate path to graves or crypts.

"I'm sure there are quite a few secrets buried here," says Abby Johnson.

Abby and her husband Ronald, professors of literature and history respectively at Georgetown University, take me to the "Public Vault," a crypt the size of a one-car garage. Built in the 1830s, the vault was used to store the bodies of public officials until the ground thawed, or until they were moved to other locations.

You need a skeleton key, of course, to get inside.

Dolley Madison slept here. As did three presidents: William Henry Harrison (1841), John Quincy Adams (1848), and Zachary Taylor (1850). Harrison's three-month stay was three times longer than his presidential term. All the presidents' bodies have since been moved to their home states.

Today, Congressional Cemetery, which boasts of being "in the shadow" of the U.S. Capitol, is overshadowed by a more prominent cemetery -- Arlington. But the Johnsons are devoted to keeping Congressional's memory alive. At least as long as they are alive. And then maybe, just maybe, beyond.