Preheat oven to 350°F (175°C).

Drain bacon and set aside.

Cut up bacon into small pieces.

Fry bacon in a skillet until crisp. Drain on paper towels.

Chop onion into small pieces.

Fry chopped onions in bacon grease until golden brown. Drain on paper towels.

Drain sauerkraut and tomatoes.

Break up whole tomatoes into smaller pieces.

In a mixing bowl, combine drained kraut, broken up tomatoes, cooked bacon, fried onion, and brown sugar.

Mix all ingredients thoroughly.

Transfer the mixture to a baking dish.

Bake in the preheated oven for 1 hour, or until heated through and slightly browned.