Though they were still traveling through territory infested with secession sympathizers, the ride from Baltimore to Washington early the morning of February 23, 1861, proved uneventful. Allan Pinkerton finally relaxed. He joined Ward Hill Lamon in sipping from a liquor bottle. Pinkerton had not been particularly thrilled with Abraham Lincoln's hard-drinking Illinois law crony tagging along—the fewer people involved in this operation the better, he believed—but Mary Lincoln had insisted that the burly bodyguard accompany them as the detective escorted her husband on the dangerous trip to the nation's capital. The blustery Lamon, who sported a uniform he designed for himself, brought along two pistols, a large bowie knife, a pair of brass knuckles, and a thick hickory stick. Though Pinkerton usually abstained from alcohol (he told his son it made him grumpy), the detective could become a cigar-smoking whisky drinker if he needed to play one working a case.
Friends and associates believed Allan Pinkerton was gifted with courage and unusual powers of observation. As a young man he had been a labor agitator, falling under the spell of Scottish revolutionaries. He now hated slavery and had become a fanatical abolitionist. He thought his parents had been atheists and he considered himself one as well. He had honed a sixth sense to anticipate criminal activity before it happened. He was stubbornly persistent, refusing to be worn down by adversity. Yet he could be a tiresome prig, who harangued employees, friends, and relatives about the virtues of honesty, integrity, and courage. He was a tyrant at home, completely dominating his wife and children. He had dark, brooding eyes set deeply under a wide brow with a heavy beard that covered his face, save for his upper lip that he occasionally shaved. He was usually dour and humorless, only occasionally showing a sense of humor. He was a master publicist, skilled at promoting his business and shameless about air brushing his image. He was a disciple of phrenology, the pseudo-medicine that determines a person's character and intellect from measurements of the head's size and shape. A phrenologist examined him, writing that the detective's brain measured twenty-three inches ("very large," the professor reported) and concluding that he was blessed with
"earnestness, enthusiasm, heartiness, whole-souledness, impetuosity and excitability."
The head of Pinkerton's National Detective Agency had reason to feel satisfied with himself that Saturday morning, February 23. His covert mission had begun a little more than a month earlier when Samuel Morse Felton, a kindly-looking Massachusetts man, hired him to investigate threats to Felton's Philadelphia, Wilmington and Baltimore Railroad from prosecessionist saboteurs. The line was a vital rail link from the North to Washington, over which Federal troops and supplies would travel if war broke out with the South. Pinkerton, whose Chicago agency specialized in tracking and capturing train robbers, arrived in Baltimore on February 1 with a squad of his best detectives. Quickly his undercover operatives infiltrated Baltimore's secret societies and paramilitary organizations that supported southern secession from the Union. Each agent was identified on intelligence reports they delivered to him by code names or simply with their initials. Using the pseudonym John H. Hutchinson, Pinkerton posed as a chatty stockbroker from Charleston, South Carolina.
It soon became clear to him that the danger was far more serious than railroad vandalism. Practically from the day they arrived, Pinkerton and his detectives began picking up the stories swirling around Baltimore of plots to assassinate the president-elect when he passed through the city. Lincoln, who by tradition remained secluded during his successful 1860 presidential campaign while others stumped for him, had departed Springfield, Illinois, on February 11 for a twelve-day, 1,904-mile, roundabout trip to Washington, D.C., with frequent halts in key states he had won to greet the public and introduce himself to the country before his inauguration the next month as the sixteenth president of the United States. He was scheduled to arrive in Baltimore shortly after noon on February 23.