1. Mix the cake according to the directions on the back of the box.
2. Once the cake is finished baking, allow it cool for 30 minutes.
3. Add a layer of cool whip on top of the cake.
4. Rinse off blue berries and strawberries.
5. Cut the strawberries in half or thin slices.
6. Place blue berries in the top upper portion of the cake.
7.Line up the strawberry slices to form the stripes of the flag.
8. Store cake in the refrigerator.