The Witness from the Hanging Tree

The diary, now a government exhibit, anchored the prosecutorial case without resolving its contradictions. Its pages—eighteen of them, water-stained and crowded with Booth’s slanting hand—had traveled from the Garrett farm to Washington in Lieutenant Edward Doherty’s satchel, passed through Colonel Lafayette Baker’s hands, and landed on Secretary of War Edwin Stanton’s desk on April 27, 1865. The nation had spent twelve days hunting the assassin through swamps and pine barrens; now it would spend twelve weeks constructing the case against those who had helped him. The method of that construction would prove as consequential as any evidence it produced.

Two facts, placed side by side, reveal the shape of what followed. On May 1, President Andrew Johnson issued an executive order establishing a nine-man military commission to try the alleged conspirators, citing the continued existence of “combinations” against the United States and the public safety requirements of a war not yet formally concluded.

On that same day, eight prisoners sat in the Old Capitol Prison on the east side of the Capitol grounds: Mary Surratt, proprietor of a boardinghouse on H Street; Lewis Powell, the twenty-one-year-old who had attacked Secretary of State William Seward with a knife; George Atzerodt, the German-born carriage painter assigned to kill Vice President Johnson; David Herold, the pharmacist’s assistant who had guided the wounded Booth across the Potomac; Samuel Mudd, the Maryland physician who had set Booth’s broken leg; Michael O’Laughlen, a childhood friend of Booth’s; Samuel Arnold, another old acquaintance; and Edman Spangler, a Ford’s Theater stagehand. They were kept apart, hooded and shackled, in cells on the prison’s upper floor. The commission would not hear its first witness for another eight days. The prisoners would not see the charges against them until the trial opened.

The gap between the legal instrument and the human reality it would process was already visible.

Why a military tribunal? The question runs through the surviving documents like a fault line. The District of Columbia possessed functioning civilian courts with established rules of evidence and the right to trial by jury. Johnson himself, as military governor of Tennessee, had administered such courts. Stanton, before the war, had built his reputation as a lawyer in civilian practice. Yet both men chose martial law over common law, and their choice shaped everything that followed.

Johnson’s order supplied the surface explanation: the “insurrection” against the national existence continued, and military commissions were the appropriate instrument for trying offenses arising from that condition. The claim was not formally wrong. The war had ended in the field—Lee had surrendered on April 9—but no peace treaty existed, and scattered Confederate forces remained under arms. Lincoln’s assassination had occurred in a federal city under military protection, against a commander-in-chief attacked while exercising his wartime functions. The legal precedent stretched back to the trial of Major John André by a board of general officers in 1780; more immediately, it drew on the Supreme Court’s reluctant acceptance, in Ex parte Vallandigham (1864), of military jurisdiction over civilians in areas of active hostilities.

But the official rationale carried institutional weight beyond its legal necessity. Stanton had spent twelve days directing a manhunt of unprecedented scope—thousands of troops deployed, telegraph lines commandeered, civil liberties suspended in the dragnet for suspects. The military commission offered continuity with that effort. Its rules of evidence were more permissible than a civilian court’s: hearsay could be admitted, the accused could not confront all witnesses against them, and the standard of proof bent toward military necessity rather than reasonable doubt. Most critically, the commission operated under the direct authority of the executive branch. Its verdicts would require only presidential approval, not the slower machinery of appellate review. Speed and control, the twin imperatives of the manhunt, would become the twin imperatives of the trial.

The commission itself was chosen to reflect this purpose. Nine officers served: Major General David Hunter as president, with Major Generals August Kautz and Robert Foster, Brigadier Generals Cyrus Comstock, Thomas Harris, Albion Howe, and Lew Wallace, and Colonels Horace Porter and James Ekin. All were active-duty officers; several had served directly under Stanton’s wartime administration. Lew Wallace, then thirty-eight, would later achieve literary fame as the author of Ben-Hur; in May 1865, he brought to the commission his experience as a field commander and his recent service on the military court that had tried the Confederate commandant of Andersonville prison. The presence of such men guaranteed professional competence. It also guaranteed that the trial would unfold within the mental world of the War Department—its assumptions about loyalty and treason, its habits of command, its recent memory of battlefield loss.

The prisoners were moved from the Old Capitol Prison to the Washington Arsenal on May 4, five days before the trial opened. The Arsenal, a fortified complex on the Potomac’s eastern shore, offered security and isolation. Its penitentiary building, constructed in 1831, contained cells arranged in two tiers around a central courtyard; the prisoners would be held on the first floor, with guards stationed at each door and windows barred against the spring air. The courtroom itself occupied the building’s northeast corner: a rectangular chamber with benches for the commission, tables for prosecution and defense, and a prisoners’ dock enclosed by a wooden railing. The public would enter through a separate door, past sentries who checked passes issued by the War Department.

The charges, when finally delivered, named three offenses: conspiring to murder President Lincoln, Vice President Johnson, and Secretary Seward; lying in wait to commit those murders; and carrying out the murder of Lincoln. The indictment named all eight prisoners as participants in a single conspiracy originating in Canada and extending through Baltimore to Washington. Booth was named as the principal, though he would never stand trial. The legal theory treated the eight defendants as extensions of his will, bound together by meetings, letters, and financial arrangements that the prosecution would spend seven weeks documenting.

The prosecution’s engine assembled itself with mechanical efficiency. Brigadier General Joseph Holt, Judge Advocate General of the Army, served as chief prosecutor, assisted by John Bingham, a congressman from Ohio who brought his reputation as a radical Republican and his experience as a courtroom lawyer. Major Henry Burnett, who had prosecuted Confederate guerrillas in Kentucky, rounded out the team. They operated from offices in the War Department, with direct access to Stanton and to the mass of evidence collected during the manhunt: the diary, the letters found in Booth’s trunk, the testimony of prisoners already interrogated, the telegrams that had tracked the fugitives’ movements.

David Edgar Herold, born June 16, 1842, had worked as a pharmacist’s assistant before the war. After the shooting at Ford’s Theater, he accompanied Booth to the home of Samuel Mudd, who treated Booth’s broken leg. Herold’s role in the escape was practical and subordinate: he guided the horse, carried the weapons, found food. At the Garrett farm, he had surrendered when the barn was surrounded, leaving Booth to face the cavalry alone. Now, in the Arsenal courtroom, he sat with the others in the prisoners’ dock, his slight frame and boyish features making him seem younger than his twenty-two years. The prosecution would make much of his loyalty to Booth, less of his evident lack of initiative.

Samuel Alexander Mudd, arrested after Booth’s death on April 26, 1865, presented a more complex target. A physician and tobacco farmer in Southern Maryland, Mudd had met Booth in November 1864, when the actor came to Charles County seeking property and introductions to Confederate agents. The meeting at which Mudd agreed to help Booth purchase horses and supplies—this was the prosecution’s theory—became one of the conspiracy’s foundational acts. Mudd’s defense, led by a senior Maryland congressman, would argue that the doctor had acted without knowledge of Booth’s purpose, that he had fulfilled his professional obligation in treating a wounded man, and that his subsequent failure to report Booth’s presence stemmed from fear rather than guilt. The distance between these accounts could not be bridged by evidence alone. It would require the commission to choose between readings of Mudd’s character, his political loyalties, and his actions in the early hours of April 15.

The prosecution’s case against Mudd rested heavily on witness testimony shaped by the reward system Stanton had established. An acquaintance named Daniel Thomas testified that in early 1865, Mudd had predicted that Lincoln and his cabinet would be killed in six or seven weeks. The specificity of this prediction—its calendar precision, its inclusion of the cabinet—made it powerful evidence of foreknowledge. Yet Thomas had come forward after the assassination, after the $100, 000 reward had been announced, after the War Department’s agents had begun their systematic interrogation of Southern Maryland’s population. His testimony was not contradicted; it was uncorroborated. The commission would have to weigh his word against Mudd’s denial, knowing that Thomas stood to profit from his information and that Mudd faced death if convicted.

Louis J. Weichmann, a boarder at Mary Surratt’s house, provided more extensive testimony. A government clerk who had rented a room at 541 H Street since the previous November, Weichmann had observed the meetings between Booth, Surratt, and the other conspirators. He had driven Surratt to Surrattsville on April 11 and 14, delivering packages whose contents he claimed not to know. His testimony was crucial in establishing the conspiracy’s existence as an ongoing organization rather than a series of isolated contacts. His own precarious position shaped it: arrested as a suspect, released after agreeing to cooperate, he testified under the implicit threat of renewed imprisonment. The prosecution treated him as a credible witness; the defense would suggest he had manufactured his account to save himself.

Mary Surratt herself sat in the dock as the only woman among the accused. At forty-two, she was older than most of her co-defendants, a widow who had converted her family tavern in Surrattsville into a Washington boardinghouse to support her children. The prosecution’s case against her rested on her ownership of the Surrattsville property where weapons were stored, her introduction of Booth to John Surratt (her son and a Confederate courier), and her presence at meetings where the conspiracy was allegedly planned. Most damaging was the testimony of John M. Lloyd, the tavern keeper who rented the Surrattsville property from her. Lloyd stated that on April 11 and again on April 14, Surratt had visited the tavern and told him to have the shooting irons ready—the carbines and ammunition hidden there for Booth’s use.

Lloyd’s testimony, like Thomas’s, emerged from the reward system. He had been arrested on April 17, held for several days, and released after agreeing to cooperate. His account of Surratt’s instructions was precise and damning—and unsupported by any other witness: no one else had heard her use the phrase “shooting irons,” and the timing of her visits allowed for alternative explanations. The defense would argue that Lloyd had invented or embellished his story to secure his own release and claim the reward money. The commission would have to decide whether a tavern keeper’s word, extracted under pressure of imprisonment, could send a woman to the gallows.

The trial’s procedural rules amplified these uncertainties. The commission allowed hearsay evidence that would have been excluded in a civilian court: statements attributed to Booth, to John Surratt (who had escaped to Canada), to Confederate agents in Canada whose names appeared in correspondence but who never testified. The defense was permitted to cross-examine prosecution witnesses but could not compel testimony from witnesses who had fled or refused to appear. The prisoners themselves were not permitted to testify under oath, though they could make unsworn statements to the court. These limitations were not arbitrary cruelties; they reflected the military commission’s origins in battlefield justice, where evidence was scarce and delay dangerous. Applied to a conspiracy trial conducted in a secured capital city, they tilted the proceedings toward the prosecution’s narrative.

The physical conditions of the trial reinforced this tilt. The prisoners were brought to court each morning hooded and shackled, seated in the dock with canvas bags over their heads—ostensibly to prevent communication, practically to mark their status as dangerous conspirators. The hoods were removed only when testimony required identification. Mary Surratt, suffering from illness and exhaustion, was permitted to sit apart from the male prisoners, but she remained under guard, her movements restricted, her contact with her lawyers monitored. The courtroom’s atmosphere, as described by contemporary observers, combined the formality of military ceremony with the urgency of public spectacle. Spectators filled the gallery, including government officials, journalists, and holders of War Department passes. The proceedings were transcribed for daily release to the press, ensuring that the prosecution’s evidence reached a national audience before the defense could answer it.

The diary, introduced as Exhibit 1, anchored the prosecution’s theory of motive. Booth’s entries, composed during his flight, mixed self-justification with theatrical grandiosity. He wrote on April 21, the night he attempted to cross the Potomac, that he had struck for his country and could never repent it, though they hated to kill. The government editors had removed certain passages—references to unnamed accomplices, suggestions of broader Confederate involvement—creating a document that supported the narrative of a self-contained conspiracy while obscuring its possible extensions. The defense objected to these excisions, but the commission admitted the edited version, noting that the original remained available for inspection. The practical effect was to present Booth as a lone fanatic surrounded by willing helpers, rather than as an agent of larger forces.

This presentation served the prosecution’s strategic purpose. A conspiracy limited to Booth and his immediate circle could be fully punished by the commission’s verdict. A conspiracy extending to Confederate officials in Canada, to Southern sympathizers in Maryland, to unknown figures in Washington itself, would raise questions that the trial could not answer and responsibilities that the government could not discharge. Stanton’s manhunt had cast a wide net; his prosecution would draw it tight, defining the conspiracy’s boundaries to match the prisoners in the dock.

The defense attorneys operated under these constraints with varying success. The Maryland congressman representing Mudd established his client’s limited contact with Booth and his professional obligation to treat the wounded. He could not overcome the testimony of Daniel Thomas or the suspicious timing of Mudd’s failure to report Booth’s presence. The attorneys for Mary Surratt attacked Lloyd’s credibility and emphasized her gender and maternal status—appeals to chivalric sentiment that the commission’s military members received with formal courtesy but no evident effect. The counsel for Atzerodt and Herold argued that his clients had acted under Booth’s domination, lacking independent criminal intent. The prosecution countered that their participation, however subordinate, was knowing and voluntary.

The commission heard its final witnesses on June 28, 1865. The closing arguments occupied the following day, with Bingham presenting the prosecution’s summation in a speech that lasted six hours. He reviewed the evidence against each defendant, weaving individual acts into the pattern of conspiracy, and concluded with an appeal to national necessity. The safety of the nation, he argued, demanded that these conspirators be punished so that the world might know the government of the United States could protect its chief magistrate and avenge his murder.

The defense attorneys spoke more briefly, constrained by the evidence record and by the commission’s evident predisposition. The Maryland congressman repeated his argument for Mudd’s innocence of knowledge; Surratt’s counsel appealed for her life; Herold and Atzerodt’s attorney emphasized his clients’ youth and subordination. None challenged the commission’s jurisdiction or the legitimacy of military trial for civilians. Such challenges had been foreclosed by the Supreme Court’s wartime rulings and by the defendants’ own precarious status. They spoke for mitigation, not acquittal, and their speeches reached ears already convinced.

The commission deliberated in closed session on June 29 and 30. Its verdicts, announced on June 30, found all eight defendants guilty of conspiracy and convicted seven of them on the substantive charges of murder or attempted murder. The sentences followed the verdicts with mechanical precision: death by hanging for Mary Surratt, Lewis Powell, David Herold, and George Atzerodt; life imprisonment for Mudd, Arnold, and O’Laughlen; six years for Spangler. The commission had accepted the prosecution’s narrative in its entirety, finding conspiracy where the evidence suggested acquaintance, imputing knowledge where intent was unclear, and distributing punishments according to a moral calculus that reserved execution for those who had struck or planned to strike, imprisonment for those who had merely assisted.

The deliberating commission had constructed its case; it had transformed the chaos of twelve days’ flight into a coherent story with clear villains and just punishments. The hooded prisoners would be led from their cells to hear their sentences pronounced, and from that pronouncement there would be no appeal except to the President himself. The machinery that had pursued Booth through Maryland and Virginia had now produced its final product: not truth, exactly, but a verdict sufficient to close the account.