Thanksgiving Day is a very important traditional holiday in America. On the fourth Thursday of each November, families and friends gather together for the occasion to celebrate with a traditional turkey dinner, usually in the mid-afternoon. Thanksgiving Day originated as a celebration of the year’s harvest and is similar to the Mid-Autumn Festival in China.

This American tradition started in 1621 before the United States of America was established. It was a huge celebration for a hard-earned harvest in the first year after the first group of immigrants arriving in the New World.

On September 6，1620，the Mayflower ship set sail from Plymouth, Devon, England, taking all the English Pilgrims to the New World. The English Pilgrims numbered about a hundred people, and left England to escape religious persecution. They had earlier fled their home in England and sailed to Holland (The Netherlands) to escape religious persecution. There, they enjoyed more religious tolerance，but they eventually became disenchanted with the Dutch way of life, thinking it ungodly. Seeking a better life, the Separatists negotiated with a London stock company to finance a pilgrimage to America.

The Pilgrims sailed sixty-six days, arrived in the New World in November of the same year. They first settled m a cornfield abandoned by Native Indians and named it Plymouth Plantation.

They worked on the land with much difficulty and were beset by a devastating plague in which half of the Pilgrim died in the long winter of 1620. In the spring of 1621，an Indian brave named Squanto and her Wampanoag tribe came to their help. The tribe taught the Pilgrims how to woric the earth and plant com, beans, pumpkins and other crops.

In late September 1621, the Pilgrims were pleased with their great harvest. To celebrate their first harvest, the Pilgrims wanted to thank God and the Native Indian. They invited Squanto and the entire Wampanoag tribe to celebrate together in a shared feast.

The first Thanksgiving dinner is said to have lasted from three days to one week. It was indeed a time of happiness, fellowship and rejoicing for the Pilgrims. They arranged a friendly treaty with the Native American Indians, built houses in the wilderness, and raised sufficient crops to feed themselves for the upcoming long winter. The Pilgrims had become the first generation of settlers in this new land holding so much promise.

This "thanksgiving" feast was not repeated the following year. But in 1623, during a severe draught, the pilgrims gathered in a prayer service, praying for rain. When a long, steady rain followed the very next day, Governor Bradford proclaimed another day of Thanksgiving, again inviting their Indian friends. It wasn't until June of 1676 that another Day of Thanksgiving was proclaimed.

On June 20, 1676, the governing council of Charlestown, Massachusetts, held a meeting to determine how best to express thanks for the good fortune that had seen their community securely established. By unanimous vote they instructed Edward Rawson, the clerk, to proclaim June 29 as a day of thanksgiving. It is notable that this thanksgiving celebration probably did not include the Indians, as the celebration was meant partly to be in recognition of the colonists' recent victory over the ''heathen natives”，so it was quite probable that the Indians would not attend it.

The first National Thanksgiving was declared by the Continental Congress in 1777. On October 3, 1789, President George Washington declared that the people of the United States should observe “a day of public thanksgiving and prayer” on Thursday, 26 November. In 1941，a Congressional Joint Resolution set the fourth Thursday of November as a national holiday for Thanksgiving.