is the way that native americans view that massacre among the many carried out against them often in the name of religion.
"Irregular thanksgivings continued after favorable events and days of fasting after unfavorable ones. In the Plymouth tradition, a thanksgiving day was primarily a church observance, rather than a feast day. But thanksgiving days did have a civil observance linked to the religious one, as in 1623. Gradually, an annual Thanksgiving after the harvest developed in the mid-17th century. This did not occur on any set day or necessarily on the same day in different colonies in America."
Thanksgiving, or Thanksgiving Day, is a holiday celebrated in the United States on the fourth Thursday in November. It has officially been an annual tradition since 1863, when, during the Civil War, President Abraham Lincoln proclaimed a national day of "Thanksgiving and Praise to our beneficent Father who dwelleth in the Heavens", to be celebrated on Thursday, November 26.
You obviously have more knowledge of the subject, so I bow to that.