Four times a year on the first Saturday of the month in February, May, August and November public open houses of the courtroom at Grant Hall, on the property of Fort McNair, in which the Lincoln assassination conspirators were tried by a military tribunal are held. During the open houses, the courtroom is manned by volunteer historians, docents and re-enactors who provide information about the tribunal and point out areas of interest inside and outside of Grant Hall.

Established in 1791 on what was known as Greenleaf Point, the military reservation named the Washington Arsenal was included in Major Pierre Charles L’Enfant’s plans for the Federal City of Washington as a major site for the defense of the capital. A federal penitentiary was built just north of the arsenal with construction completed in 1829, map shown below.

The penitentiary became the center of national attention beginning on May 9, 1865, when the trial of those implicated in Lincoln’s assassination began on the third floor of the eastern wing of the building in a newly prepared courtroom. The penitentiary is shown below. Grant Hall is the only building left standing (the upper right corner of the complex).

Grant Hall in the early 1900s shown below after much of the penitentiary had been demolished.

The eight accused – Samuel Arnold, George Atzerodt, David Herold, Samuel Mudd, Michael O’Laughlen, Lewis Powell, Edman Spangler and Mary Surratt – were tried by a military tribunal. After just two months, on June 30, the sentences were handed down and all were found guilty. Atzerodt, Herold, Powell and Surratt were hanged July 7, 1865, on gallows constructed in the penitentiary courtyard.

Arnold, Mudd and O’Laughlen received life sentences, and Spangler was sentenced to six years in prison. The group had been successful in one part of their plan, the murder of President Lincoln by John Wilkes Booth, but had failed at the other two. Powell attacked Secretary of State William Seward at his home, but managed only to injure him. Herold guided Powell to Seward’s house and, after abandoning Powell when it was clear the plan had gone astray, aided Booth in his attempts to evade authorities after his escape from Ford’s Theater. Azterodt had been assigned the task of assassinating Vice-President Johnson, but instead got drunk and didn’t go through with it. He was soon arrested for suspicious behavior.

Following the trial and with the decline in activity at the penitentiary after the Civil War, sections of it were slowly demolished, with the exception of the western and eastern extensions. The penitentiary was closed in 1881 and transferred to the Quartermaster Corps, at which time the Washington Arsenal came to be known as the Washington Barracks. Eventually, all sections of the penitentiary were demolished, except for the eastern extension that housed the third-floor, military tribunal courtroom. From 1901 to 1914, the building was used to house the Army Engineer School. It was later converted into officers’ quarters and then quarters for enlisted service members and their families. The building was eventually named Building 20, and, in the late 1900s was named after Ulysses Grant.

The Washington Barracks was renamed in 1948 for Lt. Gen. Lesley J. McNair, commander of the Army Ground Forces during World War II. Grant Hall ceased to be quarters for military personnel in 1996 and was turned over to the National Defense University for their use. NDU refurbished the rooms from quarters into offices and began using the building for NDU personnel in 2000. In the early 2000s, however, due to a failing infrastructure and lack of funding for repairs, Grant Hall was slated to be demolished. Alarmed at the thought, an NDU professor who worked in the building petitioned his congressman to halt plans for demolition, citing the historical significance of the building. Congress was able to secure historical preservation funds to save and restore the building with the condition that the courtroom be restored to the third floor during the building’s renovation. The restoration took three years – from 2009 to 2012. The third floor was restored to depict the courtroom as it appeared during the 1865 trial. Courtroom features were recreated based on artistic renderings and written descriptions of court proceedings.

During the renovation, representatives from the production company of the 2010 movie “The Conspirator,” a movie about the trial, traveled to Fort McNair to visit the sites of the tribunal and the hanging. The movie could not be filmed at Grant Hall, since the building was under renovation, so the movie was filmed elsewhere. Once filming was completed, however, the production company arranged to loan some furnishings, clothing items and props from the movie for display in the courtroom. Visitors can see Mary Surratt’s dress and bonnet, John Wilkes Booth’s hat and pocket watch, and a potbelly stove – just some of the items from the movie on display. Other artifacts and documentation found in the courtroom and adjoining rooms are from the NDU Special Collections Library. Once the Grant Hall restoration was completed, a ribbon cutting was held April 3, 2013, to officially unveil the courtroom.

The pictures below were taken from a recent open house.

Pictures taken outside Grant Hall.

Tablet in front of the tennis court next to Grant Hall.

The picture on the left below shows in blue the site of the gallows, the red boxes are where the sites of the various graves were initially located (Henry Wirz was executed separately from the four Lincoln conspirators- he was the commandant of the Andersonville prison), the red parallel lines indicate where the wall of the penitentiary was located in the pictures above (where the soldiers were standing) of the execution. The picture on the right was taken standing at ground level about where the red lines are located near the bottom in the picture on the left.

The Courtroom

Graves of John Wilkes Booth and some of the conspirators

In the next post we will cover the two-room museum adjacent to the courtroom on the third floor at Grant Hall.