Some Thanksgiving foods have changed over time. For example, most turkeys these days are bred with larger breasts to provide more white meat. Corn -- known in much of the world as maize -- has also changed. It tastes much sweeter then the starchier corn of the past.

The way Americans prepare for Thanksgiving has also changed. Economist John Anderson of the American Farm Bureau Federation says people look for ways to save time, though not everyone does.

JOHN ANDERSON: "There are a lot of us who have grandmothers who would not even think of using a store-bought pie crust. And that is kind of the least of the shortcuts that we use."

He says shortcuts like buying prepared foods for the holiday are part of a bigger trend in America.

JOHN ANDERSON: "If you think about our food in general, not just Thanksgiving dinner, but our food products in general, there has been a tremendous move over the last twenty or thirty years toward more convenience products."

Some people might not have the time or the desire to prepare a big meal, or the space for a lot of guests. Whatever the reason, John Anderson notes that more people go to a restaurant for Thanksgiving dinner than in the past.

Charity groups and religious organizations will also be busy this Thursday, serving Thanksgiving meals to the needy. The weak economy has increased the number of Americans receiving government assistance to buy food.