Mom's Potato Casserole

Ingredients

2 cups sour cream
1 can condensed cream mushroom soup
12 cup onion, chopped
2 lbs hash browns, frozen
1 cup crushed Ritz cracker
14 cup melted margarine

Directions

Combine sour cream, mushroom soup, onion and hash browns.
Mix well and pat into a 9X13 casserole dish.
Combine crushed crackers and melted margarine and spread evenly over top.
Bake at 350F for 35-40 minutes.