
Unexpected disasters or threats of judgement from on high called for Days of Fasting. Special blessings, viewed as coming from God, called for Days of Thanksgiving.
In fact, more lot of people in the USA celebrate Thanksgiving rather than Christmas. Thanksgiving Day is a secular holiday in a country that officially separates church and state so this probably makes sense.
Why Turky is the special meal for The Thanksgiving Day?
Pilgrim Edward Winslow wrote a letter about that now-famous meal in 1621 which mentioned a turkey hunt before the dinner.

Others say that as wild turkeys are native to North America, they were a natural choice for early settlers.
Special Turkey Dish:
Stuffing (also known as dressing): a mix of bread cubes, chopped celery, carrots, onions and sage stuffed inside the turkey for roasting. Chestnuts, chopped bacon or sausage, and raisins or apples are also sometimes included in the stuffing.
