In a large skillet, brown the ground beef on medium-high heat. Crumble the beef as it cooks; then drain the excess fat.
Place cooked, crumbled and drained ground beef into the Crockpot.
In a large mixing bowl, combine remaining ingredients; stir well.
Pour the sauce mixture over the cooked beef and stir well.
Place lid on Crockpot and cook on LOW 4-5 hours, stirring occasionally. If desired, add diced green pepper last 30 minutes of cooking.
Serve on toasted buns with cheese slices, lettuce and pickles, as desired.