Many of the principals and even one perpetrator in the Lincoln assassination scheme are buried at Congressional Cemetery in Southeast Washington, D.C.

Prominent  among them are:

David Herold, the young Georgetown-educated pharmacist’s assistant who went on the run with John Wilkes Booth. Davy Herold was buried near his father. Because the law required conspirators’ graves remain unmarked, when Herold’s sister died, the family buried her on top of Davy, so they would always know where his body is.

Seaton Munroe, who was present at Ford’s and was on board the USS Montauk when Booth’s body was viewed, lies in an unmarked grave, which is common at Congressional Cemetery. Only about 14,000 of the 60,000 graves are marked with headstones.

John Buckingham, the ticket taker at Ford’s and author of a book on the assassination, has a marked grave. The headline on Buckingham’s obituary called him the last person Booth talked to before he shot the president: “Last One to Talk to Booth Conversed With Lincoln’s Assassin Shortly Before the Tragedy on 10th Street Occurred.”

Peter Taltavull, the saloon keeper who served John Wilkes Booth his last drink in Washington, also lies in a marked grave. After his bar went out of business following the assassination and the shuttering of Ford’s Theatre, Taltavull became a casket maker.

The grave of James Pumphrey, who owned the stable where Booth boarded his horse, is marked by a tall obelisk.

Source: The Lincoln Assassination: Where Are They Now? by Jim Garrett and Richard Smyth