Baltimore's hostilities to the North were already well known, as just two percent of the city's voters cast their ballots for Abraham Lincoln for president while nearly half supported John Breckinridge, the Southern Democratic Party candidate. Lincoln was to pass through Baltimore on his way to Washington for his inauguration, but death threats forced the president-elect to slip through the city in the middle of the night in disguise.
Baltimore was a cauldron of secessionist feeling, and these tensions boiled over on April 18. Pro-Confederate volunteers gathered at Bolton Station to hurl insults and rocks at Pennsylvania troops as they changed trains en route to Washington. Now, on April 19, the 6th Massachusetts regiment disembarked from a train and was met with an even more hostile crowd. Tensions rose as the 11 companies of the 6th arrived. Cobblestones rained down on the soldiers as they prepared to transfer from the President Street Station to Camden Station. Shots were fired, and when the smoke cleared four Massachusetts soldiers lay dead along with 12 Baltimoreans, while 36 troops and an undetermined number of civilians were wounded.
Washington was effectively cut off from the North. In the following months, Lincoln suspended the writ of habeas corpus and hundreds of secessionist leaders were rounded up. Within six months, the Union was again in control of Baltimore.