Brown the ground round in a large skillet over medium-high heat, breaking it up as it cooks.
Drain the fat from the cooked meat.
Add salt and chopped onions to the meat and cook until onions soften, about 5 minutes.
In a small bowl, mix together ketchup, sugar, mustard, vinegar, and Worcestershire sauce.
Add the sauce to the meat mixture and stir to combine.
Reduce heat to low and simmer for 1 hour, stirring occasionally.
Serve hot on buns or kaiser rolls.