My Grandfather owned a drive-in restaurant back in the 1950's. This is his exact recipe for Coney Dogs from back in the day. It is always hit with friends and family and a nice little twist to your average hot dog!
Place the ground beef and onion in a large skillet over medium-high heat.
Cook, stirring to crumble, until beef is browned then drain.
Transfer the beef and onion to a slow cooker and stir in the ketchup, sugar, vinegar and mustard.
Season with celery seed, Worcestershire sauce, pepper and salt.
Finally, cover and simmer on Low setting for a few hours before serving.
When you have finished with your Coney Island Sauce, be sure to cook your hot dogs on the grill, stove top, or microwave!