What was ex parte merryman?

Ex parte Merryman was a significant U.S. Supreme Court case in 1861 during the Civil War that addressed the constitutionality of suspending habeas corpus. John Merryman, a Maryland resident, was arrested by military authorities for supporting the Confederacy, and he challenged his detention. Chief Justice Roger B. Taney ruled that only Congress had the authority to suspend habeas corpus, asserting that President Abraham Lincoln's unilateral action was unconstitutional. This case highlighted the tensions between civil liberties and national security during a time of crisis.