On April 19, 1861, soldiers of the 6th Massachusetts Infantry passed through
Baltimore, Maryland, on their way to Washington, D.C. A pro-secession mob attacked
them, and the first blood of the War between the States was shed. Although the lyrics
to this fervently Southern song suggest that Maryland was on the verge of joining the
Confederacy, she remained loyal to the Union -- a great relief as far as Abraham
Lincoln was concerned, for a Confederate Maryland would have proved a thorn in the
Union's side.
The poem enjoyed its first real success as a song when Jennie Cary of Baltimore and her
sister Hetty suggested singing it to the tune "Lauriger Horatius," better known to us
as "O Tannenbaum." It was adopted as the State song of Maryland in 1939 and remains so today, possibly because, as Richard Marius points out in The Columbia Book of Civil War Poetry, it has had little competition.
"Maryland, My Maryland"