Best Ever Sloppy Joes

When I was at Calvin Christian elementary school in South Holland, IL, we had one day a month when the women served these sloppy joes. They are the best-tasting sloppy joes I've ever had. We used to eat this along with potato chips and chocolate milk. Yum!

2 lbs. ground beef browned
2 cups catsup
2 Tbsp. sugar
2 Tbsp. vinegar
1 Tbs. mustard
1 tsp. Worchestershire sauce
1/2 tsp. salt
1 Tbsp. dry onion

Mix together, heat, and serve on buns.