Preheat oven to 350 degrees F (175 degrees C).
Place bacon and onions in a large, deep skillet until onions are very soft and translucent. Cook over medium high heat until evenly brown. Drain and set aside.
In a large bowl combine beans, molasses, mustard, salt, ketchup, brown sugar, dry mustard, onions and crumbed bacon. Mix well and transfer to a 2 quart casserole dish.
Bake in preheated oven, covered, for 1 hour. Uncover and bake for 1 hour more. ** 2 hours is probably too long. Check after 1 hour.
Inspired by: Mom's Baked Beans II