Thanksgiving Day in the United States started as a way of giving thanks to a good harvest.It falls on the fourth Thursday of November.The origin of the modern Thanksgiving Day is the harvest celebration in Plymouth，Massachusetts in 1621.Early Thanksgiving took the form of a special church service，rather than a feast，as is common now.George Washington announced the first national Thanksgiving Day in 1789.

　　Since 1863，Thanksgiving Day has been a yearly holiday in the United States.A more recent tradition started in 1947.Since then，we often see on television the President pardoning the turkey.

　　It is traditional for families and friends to get together for a large meal with a turkey，potatoes and other seasonal vegetables.Many of these foods are native to America and were not available in Europe when Europeans first settled in America.

　　Thanksgiving Day parades are held in some cities and towns of the US.Many football games are played

　　 and watching them is a popular activity.Some people have a four­day holiday so it is a popular time for trips out of town and to visit friends and relatives.

　　Most government offices，schools and other organisations are closed.Many offices and businesses allow staff to have a four­day holiday.Public transportation systems do not usually operate on their regular timetables.It is one of the busiest periods for travel.This can cause over crowding.Parades and football games can cause problems to the local traffic，so some states have an extra day for the Thanksgiving holiday，known as Thanksgiving Friday.

阅读短文，回答下列问题

1．When did Thanksgiving Day become a yearly national holiday?

In 1863.

2．What are the traditional foods for US people?

Turkeys，potatoes and other seasonal vegetables.