Even as Lincoln lay dying, Stanton ordered a complete lockdown of Washington, sending bulletins to all army forts and police departments along the Atlantic coast. Thinking Booth was headed towards his native Baltimore, Stanton sent troops to patrol the roads and railroad lines leading north. Only days later would authorities learn that Booth and his accomplice David Herold had actually fled toward the south, into southern Maryland—a delay that gave the two criminals a head start.
By the night of April 15, nearly 1,000 Union soldiers were seeking Lincoln’s killer. The following day—Easter Sunday—black-clad mourners packed the churches of the North. Even in the South, many people greeted the news of Lincoln’s death with sadness, realizing he had perhaps been the best chance they had of leniency during Reconstruction. Confederate leaders were quick to denounce the assassination, though many in the North saw these expressions as insincere and demanded vengeance anyway. The nation seemed on the verge of breaking apart, even as the Civil War’s end promised to bring it together again.
In Washington on April 17, investigators led by Lafayette Baker of the National Detective Police got a tip that led them to Lewis Powell (aka Lewis Payne), the former Confederate soldier who had made the grisly attempt on Secretary of State William Seward’s life the same night Booth shot Lincoln. They arrested four other alleged conspirators that same day: Mary Surratt, Michael O’Laughlen, Edman Spangler and Samuel Arnold. On April 18, Union troops questioned Dr. Samuel Mudd and his wife and searched their home, where they found a boot with Booth’s name written inside. This information finally confirmed that Booth had gone into southern Maryland, and was probably headed for the Potomac River and Virginia. Stanton sent more troops to the region, and ordered every available Union warship to patrol the Potomac south of Washington.
Lincoln’s funeral took place at the White House on April 19, with thousands of mourners lining the streets to pay their last respects. The following morning, soldiers arrested George Atzerodt in Maryland; Atzerodt had been assigned to kill Andrew Johnson, but had spent the evening of April 14 drinking in a bar instead. Now only three of the prime suspects remained at large: Booth, Herold and John Surratt. Stanton offered a staggering $100,000 reward for their capture—the equivalent of some $1 million today.
While all this was going on, Booth and Herold were hiding out in a thicket of the Maryland woods, where they would spend a total of five days. On the night of April 20, they attempted to row across the Potomac, but lost their way and remained in Maryland. They finally got to Virginia on April 24, after crossing the Rappahannock River on a ferryboat with the help of several Confederate soldiers, and found their way to a farm owned by Richard Garrett.
Members of the 16th New York Cavalry regiment traced Booth and Herold to Garrett’s farm, and in the early morning hours of April 26 surrounded the tobacco barn, where Booth and Herold were hiding. A brief standoff ensued, and the soldiers set fire to the barn in an attempt to smoke the two men out. Herold surrendered, but Booth refused, and was shot to death by one of the soldiers, Sgt. Boston Corbett.
President Johnson ordered the eight defendants accused in the Lincoln assassination conspiracy to be tried by a military commission, and testimony began on May 12 at the Old Arsenal Building in Washington. By order of Secretary Stanton the defendants (except Mary Surratt and Samuel Mudd) wore canvas hoods covering their heads during the trial. To the War Department, the trial was an opportunity to prosecute not just the alleged conspirators themselves, but also Jefferson Davis and the rest of the Confederate leaders, whom they believed had fostered such conspiracies in a desperate attempt to salvage the war effort.
Of the eight defendants, Powell, Herold and Atzerodt had been deeply involved in Booth’s plot to kidnap President Lincoln, and had played direct roles in the violent events of April 14. Mary Surratt, the owner of the boarding house where Booth and the other conspirators met, was accused of sheltering the conspirators and helping them plan the killings; her son, John Surratt, was one of Booth’s main co-conspirators, and had introduced the actor to both Herold and Atzerodt. He was not in Washington during the assassination, and in the confusion afterwards fled the country, living as a fugitive in Europe while his mother stood trial.
The other four defendants had weaker connections to the conspiracy. Arnold, a longtime friend of Booth, was tied to the original kidnapping plot by a letter he wrote to Booth in March 1865; he later backed out, and was not in Washington when the assassination took place. Mudd, a staunch Confederate sympathizer, was approached by Booth in connection with the kidnapping plot but claimed not to recognize him when he showed up at his southern Maryland farm on April 15. He treated the actor’s leg (which he broke when he jumped to the stage at Ford’s Theatre) and sent him on his way. Spangler, a stagehand and carpenter at Ford’s, had been enlisted to hold Booth’s horse outside the theater, while O’Laughlen—another Maryland friend of Booth—was also tenuously linked to the kidnapping plot.
Justice acted swiftly against the Lincoln conspirators. On June 30, after meeting in secret session, the commission delivered its verdicts: Powell, Herold, Atzerodt and Mary Surratt were sentenced to death; O’Laughlen, Arnold and Mudd received life sentences; Spangler got a six-year prison term. A week later, on July 7, Powell, Herold, Atzerodt and Mary Surratt were executed by hanging in the courtyard of the Old Arsenal Building. While Arnold, Mudd and Spangler were all eventually pardoned by President Johnson and released, O’Laughlen died in prison of yellow fever in 1867. The final conspirator, John Surratt, was captured in Egypt in 1866 and tried before a civilian court the following year. The jury was unable to reach a verdict, and Surratt was released; he lived until 1916.
Over the years, critics have argued that the procedures, verdicts and sentences of the Lincoln assassination conspiracy trial were unfair and unduly harsh, and by modern standards they certainly may have been. The decision to execute Mary Surratt—who despite public protests and a petition to President Johnson for clemency would become the first woman put to death by the federal government—and give a life sentence to Dr. Samuel Mudd were particularly controversial. But for a war-torn and grieving nation, stricken by the violent murder of its leader just as the difficult work of rebuilding the Union was beginning—perhaps it could be no other way.