Everyone knows about Abraham Lincoln's assassination in 1865, but not everyone knows there was also a conspiracy to kill him four years earlier in 1861, literally on his way to Washington, DC, for his first inauguration. The conspirators were part of a secret society that didn't want an abolitionist in the highest office. They planned an elaborate scheme to assassinate the brand new President in Baltimore as Lincoln's Inauguration train was headed to the Capital. The plot was foiled thanks to famed detective Allan Pinkerton, who infiltrated the group with undercover agents, including one of the first female private detectives in America. Had the assassination succeeded, there would have been no Lincoln presidency, and the Civil War would've had a potentially far different ending. This is the story of the secret plot that nearly changed history.