I've been thinking about this too, this is what i've come up with.
I've always thought that American cuisine is a little different for one big reason. Most world cuisines developed over thousands of years with local foods and cooking practices. American cuisine has had a constant influx of immigrants for the past 500 years on top of native north and south american foods. Plus, America has a wide range of climates, so the ingredients and cooking practices are all over the place. American cooking is a collection of regional styles. Many cultures are, but there are huge climatic differences between Louisianna and Alaska. Not to mention the explosion of foods and ingredients in the past 30-40 years.
It's helpful to think of the region styles New England, Southern, Cajun, Midwestern, Western, Tex-Mex, Cal-mex, California cuisine, Pacific NW, Hawaiian.
Another way to look at it is the foods that originated here. Chili with beans, clam or fish chowder, fried clams, succotash, sweet potatoe pie, gumbo, jambalaya, strawberry shortcake, the chocolate chip cookie, blueberry pie, roast turkey with bread stuffing, cranberry sauce and pumpkin pie, maybe brownies. Like it or not, hot dogs, hamburgers and tuna noodle casserole get included.
American cakes and cookies are very different from european cakes and cookies. Pineapple Upside Down Cake, although it originally used various fresh or dried fruits. Although we didn't invent open fire grilled meats, our barbeque is very different from other cultures. Meatloaf is distictly American, but it's basically hot pâté made with inexpensive ingredients.
It's also helpful to think of the region styles New England, Southern, Cajun, Midwestern, Western, Tex-Mex, Cal-mex, California cuisine, Pacific NW, Hawaiian.
Another way to think about it, what are the new world ingredients? Turkey, squash and pumpkin, corn, avocados, peanuts, chilis and peppers, tomatoes, potatoes, sweet potatoes, wild rice, cod and salmon, crab and lobster, venison, blueberries, chocolate, cranberries.
Sorry, I got carried away.