In Febuary 1861, President-Elect Abraham Lincoln went on a tour to multiple states on the way to his Presidential Inauguration. Lincoln was notified by Samuel Morse Felton, the President of the Philadelphia, Wilmington and Baltimore Railroad, that there was a cessionist plot to capture Washington, D.C. and to stop the inauguration of Lincoln. The President was notified of another plot to assassinate him on the way from the Calvert to the Camden train station in Baltimore City.
Lincoln was recommended to end the rest of his tour and to take a midnight train back to Washington, D.C. At first Lincoln wanted to continue his tour, so that the American people would get to better know him, but he decided to the risk to his life was too great if he continued to speak publicly. On the return train to Washington D.C., one women pretended to be Lincoln’s sister and Lincoln himself wore a disguise while sitting in the back cabin. The Pinkertons, and many others, also helped with the protection of the President-Elect during tour and on his voyage to Washington, D.C.
When Lincoln came back to Washington, D.C. he was inaugurated, on the U.S. Capital steps, while the new dome was being constructed.
Here is a Smithsonian Institute documentary on the failed assassination attempt on President Lincoln.
Samuel Morse Felton’s son Samuel Morse Felton II was named the “General of Military Railways” during World War I.