It was the day after "Maryland, My Maryland" was first published, that Lincoln suspended the writ of habeas corpus in Maryland. Subsequently, as Virginia's secession from the Union became imminent, Lincoln sent the Union Army to occupy Annapolis and Baltimore, and declared martial law. Over the course of the next few months, the Union arrested many Marylanders suspected of Southern sympathies, including 30 members of the State legislature, a US Congressman representing Maryland, the mayor and police commissioner of Baltimore, and most of the Baltimore city council. Union troops went door to door confiscating weapons.
These illegal and unconstitutional actions against Maryland cost Lincoln his life.
'Sic Semper Tyrannis'