With Maryland on the brink of insurrection in 1861, President Abraham Lincoln worried that the Capital might be cut off from the North. He suspended the writ of habeas corpus at points along the route from Philadelphia to Washington. The action was contentious but wasn’t as vehemently condemned as the nationwide suspension he authorized the following year to suppress rebellion against the first draft for military service.
Presidential Proclamation Number 94 1862
National Archives, General Records of the U.S. Government