In a large frying pan, fry bacon until crispy, drain on a paper towel then crumble the bacon. Reserve about 1/4 cup of the bacon grease in the pan
Finely chop the onions and saute them over medium heat in the bacon drippings until onion is clear. If your bacon didn't produce enough grease, just add a little oil to your pan if necessary.
Add in all the remaining ingredients into the pan (including cooked bacon) and stir.
Pour bean mixture into an ungreased 9x13-inch baking dish and bake covered (with aluminum foil) for about an hour (until brown and bubbly).
If you like your beans to be a little less sauce-y, take the aluminum foil off and bake for about another 20-30 minutes (stirring the beans occasionally.) The longer it cooks, the thicker it gets.