The first Thanksgiving celebration (as we think of it) happened after the third summer of Plymouth colony. For the first two years, the Pilgrims abided by the Mayflower Compact, which called for strict socialism. As a result, they didn't grow nearly enough food, and starvation killed half the population each winter. (Not having any actual farmers in the first group didn't help any, either.)
The third spring, they allocated a plot of land to each family to work for their own benefit. That fall, despite a minor drought, they enjoyed a bountiful harvest. There was more than enough food for everyone. So they held a celebration of thanks giving to God for the harvest, and for teaching them the evils of socialism.
So let us today give thanks to almighty God for the bountiful harvest, a healthy, happy family, and for teaching us the evils of full socialism. May those with eyes see. May those with ears hear.