Wow, Gail! I'm not alone. I bet only people of a certain age know we called them that. Today, the term refers to ground hamburger in tomato sauce on a bun.
I loved my sloppy joes, pleated skirts, bobby socks, and dirty saddle shoes - they had to be dirty. When you got a new pair, the first thing you did was look for a coal bucket so you could dirty them up before wearing them.