Some Southerners didn’t take kindly to famous native Marylanders who were unabashedly pro-Union. From the Richmond Daily Dispatch June 3, 1864:
Edwin Boot[h] at the North.
–This young actor, a native of the State of Maryland, and whose engagements in the South previous to the war were attended with so much success, has lately been performing at the North for the benefits of the Sanitary Committee, When [t]old in Washington by a Southern lady a short time since that the people of the South would surely remember him in this matter, he repeated: “He did not care what they remembered? He knew no country but the Union.–no flag but the stars and stripes.” So much for Edwin Booth!
According to Wikipedia sometime in 1864 Edwin Booth performed in Julius Caesar with his brothers John Wilkes and Junius, Jr. It was the only time they appeared together on stage.