While Maryland was considered part of the north, and fought on the side of the Union during the Civil War, it is still south of the Mason-Dixon line, and African-Americans living there were lynched into the 1930s. In 1931, Pulitzer Prize-winning editorial cartoonist Edmund Duffy joined with H.L. Mencken in a years-long newspaper campaign to fight attacks on black American citizens.

https://www.baltimoresun.com/features/retro-baltimore/bs-md-retro-baltimore04-story.html