Thanksgiving:: A Righteous Holiday or Sacrificial Commemoration

We have known this holiday known has Thanksgiving since we were small. The holidays of pilgrims and Indians and turkey and pumpkin pie. This celebration is supposed to commemorate the gathering of the people into a celebration. But is this truly a holiday or the commemoration of a tragic event.
Have you ever thought of all that happened when we came to this land? We fought for land and killed many people-- Indians. We stole from people and claimed it as our own and we make a grrrreat celebration out of it. This holiday is made to be all about the pilgrims and how everything was peaceful with the Indians back in the day but it wasn't. Not just about Thanksgiving, Indians were killed in many different battles and for no specific reason really as to steal their land and call it our own. I don't know about you but it doesn't seem to make much sense to me.
In this sense, is Thanksgiving also not considered to be a ritual sacrifice within itself? We get a turkey, although most do not kill it themselves, and eat it in the commemoration of a past event. I thoroughly enjoy turkey as much as the next person don't get me wrong, but certain holidays with specific animal products set to them seem to be like a set ritual. I guess it would seem different if Thanksgiving wasn't set to the traditional turkey or Christmas to the ham. It's like the Gods or God are saying "On this day of every year we would enjoy a turkey/ham/whatever" and we go along with it to please them. Much like a ritual sacrifice.

P.S. I will be enjoying the traditional turkey but not actually consider myself celebrating Thanksgiving. In my opinion it is all in the mindset and turkey is delicious. Sorry.