On 29 April 1861, Maryland’s legislature voted 53-13 against convening a secessionist convention. However, they also voted not to reopen rail links with the north, and requested that Lincoln remove federal troops from the state. Lincoln responded by giving the army limited authority to suspend habeas corpus. When the state militia demolished several railroad bridges, Militia Lieutenant John Merryman was arrested, charged with treason, and placed in custody.
Chief Supreme Court Justice Taney issued a ruling in Ex parte Merryman stating that the President could not authorize the suspension of habeas corpus, but Merryman remained in custody, with Lincoln explaining that he had been authorized because Congress had been out of session at the time, and an invasion or rebellion could have taken place.