A sarcastic phrase meant to downplay the complaint or misfortune of another person, similar to playing the world's tiniest violin with one's fingers.
It is a reference to the assassination of President Lincoln. Can be substituted with any phrase referring to a tragic event, such as, "Other than that, how was the flight, Sullie?"
"I just found out I have to work this weekend."
"Other than that, how was the play, Mrs. Lincoln?"