John Wilkes Booth and John Harrison Surratt were the leaders of the conspiracy in Washington, they having proposed to their co-conspirators in Canada to accomplish for them the assassinations they had planned.

They were stimulated by their intense hostility to the administration of President Lincoln and desire for the establishment of the Southern Confederacy, and also by the delusive idea of winning enduring fame and the lasting gratitude of their countrymen of the South for being thus the instruments of retrieving the fortunes of their dying cause. But in addition to these considerations, they had large promises of pecuniary reward. They were, in fact, the hired assassins of Jefferson Davis and his Canada Cabinet.

These two men had been engaged for months in making their preparations for the assassination of the President, Vice-President, Secretary Seward, and General Grant. They visited and conferred with the Canada conspirators from time to time during the summer and fall of 1864, and early winter of 1865. They traversed the counties of Prince George, Charles, and St. Mary's, Maryland, lying along the north side of the Potomac below Washington, to prepare the way for escape by securing confederates along the contemplated route who would assist in facilitating their flight by aiding them in their progress, or by concealing them if necessary. Booth had spent some time in this work during the fall and early winter, making himself familiar with the geography of the country, roads, etc., under the pretence that he desired to purchase lands in Maryland. He found in Charles County Dr. S. A. Mudd, who sympathized with his plans, and entered into them at least so far as to pledge him any assistance he could give him in making his escape. Mudd also visited Booth two or three times in Washington during the winter, introducing him on the occasion of his first visit to John H. Surratt; and in the course of these visits he was always found in company with Booth and others of the conspirators who were to take an active part in its accomplishment, and was no doubt kept well informed of the progress of their preparations, and of the time when it would be attempted after that had been determined upon. Surratt also spent much time during the winter in this part of Maryland, in preparation for the work. Being at home there, he could render Booth valuable assistance by procuring friends who would aid him in his flight, and in getting him across the Potomac at the selected point. As this was on the line of a regular underground mail route between Washington and Richmond, with which Surratt was familiar, he, of course, had no difficulty in making satisfactory arrangements, the great mass of the population in all of these counties being intensely disloyal.

They had selected and arranged with Payne, Atzerodt, O'Laughlin, Arnold, Herold, Spangler, and numerous other parties who were never made known, to take an active part in the work of assassination, or to aid them in their escape. Booth and Surratt had provided horses for the occasion, and, with Atzerodt and Herold, were known to a number of liverymen of whom they were liberal and frequent patrons.

Surratt provided quarters for Payne at the Herndon House, representing him to be a delicate gentleman, and stipulating that his meals should be served to him in his room. Atzerodt, who was to have assassinated the Vice-President, had taken a room at the Pennsylvania House. Booth, being an actor, and familiar with the routine of the play and the work of the assistants on the stage, having selected Ford's Theatre as the place for the accomplishment of his purpose, proceeded to make himself at home amongst the habitues of that establishment. He was a very handsome man, stylish in his dress, dissolute in his habits, a constant and free drinker, generous in the expenditure of his money on his vices of smoking and drinking, and of great personal magnetism. He soon ingratiated himself with the employees of the theatre, and became a general favorite.

It was necessary that he should have a co-conspirator at the theatre to assist him in making his escape. He had labored hard with an actor in New York by the name of Chester, with whom he was acquainted, to engage him in the conspiracy, that he might station him at the door of his exit, to see that his way should be clear and the door open at the critical moment, for which service he offered to pay him three thousand dollars; but Chester, after several interviews and much importunity, absolutely declined, and begged Booth never to mention the matter to him again. Failing to secure Chester, he turned his attention to Edward Spangler, an employee at the theatre. Spangler was a man of dissipated habits, low moral tone, and little intellectual culture, and being politically in sympathy with Booth, he was easily led by him into the conspiracy. Booth had had a shed fitted up as a stable in an alley back of the theatre, and had kept his horse in it occasionally for some time previous, that he might have it convenient when the supreme moment should have arrived, without exciting suspicion. To reach the private box fitted up on the occasion for the occupancy of the President and General Grant, with their wives, it was necessary to pass through two doors. The first led into a passage behind the box, the second from this passage into the box. To prevent any one from following him into the passage and hindering the accomplishment of his purpose, Booth had cut, himself, or more likely had had Spangler, who was a kind of rough carpenter, cut a mortise in the plastering of the passage wall, in such a position with reference to the door that the end of a wooden bar, three and a half feet long, which had been prepared for that purpose, could be inserted in the mortise, and the other end placed against the panel of the door so that it could not be opened from the outside.

That ingress to this passage might not be prevented by the bolting of the door by the President and his party after entering, the screws of the fastenings had been drawn, so that it could be easily pushed open. A hole had been bored through the door to the box, opposite where the President's chair was placed, with a small bit, and reamed out with a knife, so that Booth could, after gaining the passage and barring the door behind him, peep through this hole and assure himself of the exact position of his intended victim. The manner in which all of these arrangements had been made, the mortise in the plastered wall, the bar of wood fitted to the mortise, and in length having been exactly prepared to fit against the panel of the door and act as a brace, show that all these preparations had been made with the greatest forethought and care.

About three weeks previous to the assassination, John H. Surratt, Herold, and Atzerodt brought to the tavern at Surrattsville, in Maryland, about ten miles below Washington City, owned by Mrs. Surratt, and at the time occupied by a man by the name of Lloyd, two carbines, with ammunition, a monkey-wrench, and a piece of rope. Surratt asked Lloyd to take charge of these things and keep them secreted, saying they would be called for before a great while, at the same time showing him a suitable place about the house in which to hide them. The Surratt family had lived in this house and kept a country tavern until within a few months previous, when they had removed to Washington, renting their tavern to Lloyd, so that Surratt was much more familiar with the house than Lloyd. These things, as we shall see, were placed there for the use of Booth and his companion in their flight after the assassination. As a precautionary measure, Booth, on the Tuesday before the assassination, sought an interview with Mrs. Surratt, who shortly after that interview discovered that she had some private business at Surrattsville that had to be attended to that day, and so she asked Mr. Wiechmann, a young man who had been a boarder at her house for several months, to drive her down, saying that she wanted to go and see a Mr. Nothey who owed her some money. She then sent Wiechmann to Booth, to get his horse and buggy for the drive. Booth told Wiechmann that he had sold his horse and buggy, but gave him ten dollars with which to procure one. Meeting Lloyd on the way down, driving up to Washington, they stopped; Lloyd got out of his buggy and went to the side of Mrs. Surratt's buggy, on which she was sitting, when Mrs. Surratt told Lloyd, as he afterwards testified, in a low voice, so that Wiechmann did not hear what she said, to have those shooting irons ready, or handy, as they would be called for before long. On the day of the assassination Booth again had a private interview with Mrs. Surratt, after which she again asked Wiechmann to drive her down to Surrattsville, claiming the same errand as before. On this occasion she sought an opportunity for a private interview with Lloyd, when she told him to have the carbines handy, as they would be called for that night, at the same time handing him a field-glass, which Booth had given to her, and telling him to have two bottles of whiskey ready.

John H. Surratt left Washington for Richmond on the 25th of March and returned to Washington on the 3d of April, leaving for Montreal on the evening of the same day. He showed to Wiechmann—an old college friend and, at this time, a boarder in his mother's house—nine or eleven twenty-dollar gold pieces, and sixty dollars in greenbacks, on his return from Richmond. Surratt, in his Rockville lecture, admits that he received two hundred dollars in gold from Benjamin to pay expenses and remunerate for services. Surratt left Washington for Canada on the evening of the 3d of April, and we find him, by the evidence, in Montreal on the 6th, where he delivered to Thompson a cipher dispatch from Jefferson Davis, and a letter from Mr. Benjamin, of Davis's Richmond Cabinet. After reading these documents, Thompson, laying his hand on them, said, "This makes the thing all right." The sanction of the rebel president to his arrangements with the assassins had been obtained, and authority also for the expenditure of funds to fulfil the contract. The Canada conspirators who were to take a part prepared at once, and started for the States, boasting to their friends that they would hear of the death of Old Abe and others before ten days. This was on the 8th of April, and nothing now remained but to find, and use, an opportunity; and Booth selected the appearance of the President at the theatre as affording the opportunity he sought, and proceeded to make all his arrangements accordingly.

All things were now ready. Booth had selected the route for his escape and had provided to be furnished with a field-glass, two carbines, and two bottles of whiskey at Surrattsville, having sent a notice to Lloyd to have them ready, as they would be called for that night. He had provided horses from a livery-stable for himself and Herold, who was to accompany him. He had also provided a horse for Payne, whose part was to murder Secretary Seward. He had assembled his assistants in Washington, to one of whom, Michael O'Laughlin, he had assigned the task of the assassination of General Grant; and having made these preparations, he spent the day and afternoon of the 14th of April looking after the matter generally, and keeping up his courage, or rather recklessness, with frequent potations of whiskey. To Payne he had given a one-eyed bay horse, which he had purchased of a man by the name of Gardner, a neighbor of Dr. Samuel Mudd, in Charles County, Maryland. Mudd accompanied him, and introduced him to Gardner as a man who was desirous of purchasing land in that part of Maryland, and who wished a good driving horse that he could use for a short time. During the afternoon of the 14th, Booth, Herold, and Atzerodt hired horses from liverymen, and were to be seen riding here and there about the streets of Washington, frequently stopping at saloons to refresh themselves with that which obtunds all moral sensibility and makes men reckless in wickedness. Booth was acting the part of a general mustering his forces for the conflict, part of which he thus displayed openly, but keeping another part in concealment. He kept himself in active communication with all, and delivered his orders and instructions. Feeling the full force of the responsibility of his engagement, and earnestly intent on its complete and thorough accomplishment, he attended in person to every detail to make failure, if possible, an impossibility.