Roger B. Taney in the context of "Taney County, Missouri"

During the American Civil War (1861–1865), Maryland, a slave state, was one of the border states, straddling the South and North. Despite some popular support for the cause of the Confederate States of America, Maryland did not secede during the Civil War. Governor Thomas H. Hicks, despite his early sympathies for the South, helped prevent the state from seceding.

Because the state bordered the District of Columbia and the opposing factions within the state strongly desired to sway public opinion towards their respective causes, Maryland played an important role in the war. The Presidency of Abraham Lincoln (1861–1865) suspended the constitutional right of habeas corpus from Washington to Philadelphia. Lincoln ignored the ruling of Chief Justice Roger B. Taney in "Ex parte Merryman" decision in 1861 concerning freeing John Merryman, a prominent Southern sympathizer arrested by the military.