By 1817, Congress had set aside sections of the cemetery for legislators and government officials. For those buried elsewhere, identical cenotaphs were erected -- 168 of them, designed by Benjamin Latrobe, the architect of the Capitol. Each is a large square block with recessed panels set on a wider plinth and topped with a conical point. They march in rows like stone sentries, memorializing senators, representatives, and one non-congressman: William Thornton, the first Architect of the Capitol. From 1823 to 1876, Congress funded the cemetery's expansion, paving, fencing, and the public vault used for temporary interment. Presidents' funerals passed through here -- William Henry Harrison in 1841, Zachary Taylor in 1850 -- with processions stretching two miles from the White House.

On a summer day in 1864, an explosion ripped through the Washington Arsenal, killing a woman supervisor and twenty teenage girls who had been packing explosives and cartridges. Most were Irish. President Abraham Lincoln led the funeral procession to Congressional Cemetery and attended the graveside ceremonies. A monument was later erected over the graves of sixteen victims -- a marble column topped with a sculpture of a grieving young woman, carved by local artist Lot Flannery. Lincoln's assassination conspirator David Herold is also buried here, as is Lewis Powell, another conspirator believed to have hidden overnight in the cemetery's public vault while fleeing. First Lady Dolley Madison spent two years in that same vault while funds were raised for her reinterment at Montpelier -- the longest known interment in the cemetery's public resting place.

After Congress stopped funding the cemetery in 1876, decline set in slowly and then all at once. By the 1970s, monuments and burial vaults were crumbling, buildings rotted from deferred maintenance, and drug dealers and prostitutes had taken over the grounds. Christ Church, the cemetery's owner, lacked the resources to intervene. In 1976, management passed to the Association for the Preservation of Historic Congressional Cemetery. Progress was glacial until 1997, when the K-9 Corps was organized -- a group of dog owners who paid membership fees for the privilege of walking their dogs off-leash on the grounds. Their presence drove out the drug trade. Today the K-9 Corps provides roughly twenty percent of the cemetery's operating income, and the program has been nationally recognized for creative use of urban green space.

Congressional Cemetery holds one vice president, one Supreme Court justice, six Cabinet members, nineteen senators, and seventy-one U.S. Representatives. But the grounds are not exclusively political. Mathew Brady, who documented the Civil War through his camera lens, rests near Belva Ann Lockwood, the first woman attorney permitted to practice before the Supreme Court. Tom Lantos, the only Holocaust survivor elected to Congress, lies near Leonard Matlovich, the Air Force veteran and gay rights activist whose gravestone reads, "When I was in the military, they gave me a medal for killing two men and a discharge for loving one." The cemetery claims to be the only one in the world with a dedicated LGBTQ section. In 2013, fifty-eight eco-goats were brought in to clear poison ivy from the surrounding woods -- the first use of goats inside the Beltway, an event that drew coverage from the BBC, Al-Jazeera, and Tokyo TV. At Congressional Cemetery, American history is not curated. It simply accumulates.