Have you heard of the melting pot analogy?
It goes like this: the United States is a country where immigrants from different cultures around the world come together. Like the ingredients in a melting pot, each person contributes something special to the mixture.
Then, with a little bit of heat, the ingredients melt together forming the United States—a unified culture made unique (and more delicious) by the diversity of ingredients added to it.
Enter The Salad Bowl Theory:
Both the melting pot and the salad bowl are made up of unique ingredients. But, instead of melting its contents and blending them together, a salad maintains the individuality of each individual ingredient . The salad still tastes delicious in the end, but it does so by embracing each ingredient, not by changing them.
Both analogies offer an example of the importance of immigrants and diversity to American culture. We just prefer the salad bowl analogy because it embraces our cultural differences instead of hiding them.