Today marks the 150th anniversary of the occupation of Baltimore by Federal troops in 1861 after a period of discontent and rioting that swept the city and parts of the border slave state in the wake of the firing upon Fort Sumter. This trouble and that posted earlier in Missouri illustrated the precarious situation in the border states that remained in the Union.
Maryland had strong ties to the South. A slave state, it place the capital, Washington in an interesting position, surrounded by slave states. When Virginia seceded in April, fears of Maryland leaving grew in the city. The inauguration of Abraham Lincoln intensified feelings among the Southern leaning citizenry, especially after his calling for volunteers, which meant Union troops would be passing through Maryland, Baltimore in particular.
The tension grew to violence, as soldiers and civilians were killed in several days of rioting over the war and the course of the state. In the aftermath, Benjamin Butler, who later became famous for his order against the women of New Orleans, commanded the remainder of a Union force sent to maintain communication lines to Washington, and occupied the city, placing it under martial law. Thus began 150 years ago an occupation of an American city. Attempts at secession were tried, but failed, and, despite the turmoil, Maryland remained in the Union.
Civil War History 