In 1621, after the difficult, unrelenting labor of starting a colony, the Pilgrims, using planting techniques taught to them by the native Wampanoag tribe, celebrated their first successful harvest with a feast, which they shared with their native American neighbors (who we later almost wiped out, there being only about 400 survivors sixty years later, following King Philip's War).

This is the most important, most truly American holiday (the Canadians have a similar observance, but they're just our little northern clones anyway, right?). It's a day of forgiveness, a day when families travel from across the country to get together, eat our traditional meal, celebrate our mutual heritage, and nestle securely in the bosom of warmth and family.