Thanksgiving celebrates a shared meal between Christian Pilgrims and Native Americans in 1621. It is not a religious holiday, but has an interesting, semi-religious history.
Thanksgiving is a national holiday that is celebrated primarily in North America. It's celebrated on the fourth Thursday in November in the United States and on the second Monday in October in Canada.
Although Thanksgiving is rooted in the history of the Pilgrims, who were Christian "Separatists," the holiday is gnerally no longer considered a Christian holiday or a religious holiday. but simply as an occasion to gather with family, eat food, watch football and parades, and be thankful for the blessings of life.
The First Thanksgiving
The story of the "first Thanksgiving" in 1621 began when colonists at Plymouth went out "fowling," probably for food like geese and ducks rather than the harder-to-catch turkeys, since they reported they "in one day killed as much as... served the company almost a week." Other items on the menu probably included fish, eels, shellfish, stews, vegetables, and beer. This led to the first Thanksgiving dinner.
After the successful hunt, 90 or so Wampanoag made a surprise appearance at the settlement's gate. Although this may have been initially alarming to the colonists, who numbered about 50, the groups socialized peacefully over the next few days. The Wampanoag contributed venison to the feast and joined the Pilgrims for activities like shooting guns, running races and drinking liquor. The end result of the rather disorderly party was a treaty between the two groups that lasted until King Philip's War in 1675.
The early colonists of New England regularly celebrated "Thanksgivings" after a military victory, end to a drought, or other favorable events. For example, a national Thanksgiving holiday was proclaimed upon the enactment of the Constitution.
Christian Separatists generally shunned holidays, but periodically proclaimed a "Day of Thanksgiving and Praise" in response to evidence of God's favor or a "Day of Humiliation and Fasting" in response to God's perceived displeasure. These feast and fast days were usually held on the day of special sermons called "Lecture Day," which was Thursday in Massachusetts.
Thanksgiving as a National Holiday
The first general day of Thanksgiving was proclaimed by President George Washington, who at the request of Congress recommended Thursday, 26 November, 1789, to the people of the United States "as a day of public thanksgiving and prayer to be observed by acknowledging with grateful hearts the many and signal favours of Almighty God."
However, after 1798 the proclamation of a Thanksgiving Day was left to the states, for Southerners were slow to adopt the custom, some objected to the federal government's involvement in religious observance, and others disliked the partisan speeches and parades that became customary.
Thanksgiving Day only became an official holiday once Northerners dominated the federal government. In 1863, after the famous battle at Gettysburg, Abraham Lincoln proclaimed a national day of Thanksgiving to be held on August 6. Soon the public began to ask for an annual observance, so in 1867, President Andrew Johnson established the last Thursday in November as the official Thanksgiving Day.
Two attempts were made by later presidents to adjust the date: in 1870 Ulysses S. Grant moved it to November 18 and from 1939 to 1941, Franklin D. Roosevelt moved it back a week to extend the Christmas shopping season.
The tradition of Thanksgiving football games began with a game between Yale and Princeton in 1876. In the late 1800s, parades of costumed revelers became common, and in 1924 the first annual Macy's parade was conducted. Giant balloons were added in 1927 and have been a staple ever since.
Thanksgiving in Canada
In Canada, Thanksgiving Days also arose during the colonial period. The earliest Canadian Thanksgiving was held in 1578, when Martin Frobisher held a ceremony in present-day Newfoundland to give thanks for a safe arrival in the New World.
In 1879, Parliament established a national Thanksgiving day on November 6; since 1957, Thanksgiving Day has been celebrated in Canada on the second Monday in October.
Thanksgiving Customs and Observances
Today, the Thanksgiving holiday is a time when families gather together to eat food like turkey and trimmings, watch or play football, and enjoy parades. Its meaning has also changed over the years: "The holiday associated with Pilgrims and Native Americans has come to symbolize intercultural peace, America's opportunity for newcomers, and the sanctity of home and family." 
In the United States, Thanksgiving is an official holiday on which all public business is suspended. It has become traditional for the President to pardon a lucky turkey from gracing anyone's dinner table on Thanksgiving Day. Once, after pardoning "Liberty," the freed bird, President Bush said, "Through the generations, our country has known its share of hardships. ... Yet, we've never lost sight of the blessings around us: the freedoms we enjoy, the people we love, and the many gifts of our prosperous land." 
The Friday after Thanksgiving has become the unofficial start to the Christmas season. Many stores host sales on this day to encourage shoppers to begin their Christmas shopping, so it is also the day to either flock to the malls or avoid the malls completely, depending on one's temperament.
- "Thanksgiving Day." Encyclopædia Britannica. Encyclopædia Britannica Premium Service, 2004. .
- Elesha Coffman, "Eat, Drink and Relax." Christian History & Biography Newsletter, November 16, 2001.
- "Thanksgiving Day." Catholic Encyclopedia, 1912.
- The Annual Pardoning of the Thanksgiving Turkey - WhiteHouse.gov. Nov. 21, 2004.