A couple of years ago, I tackled the main Thanksgiving myth (see #69) about the first Thanksgiving and also the one about popcorn and Pilgrims (see #70). This year I'll send you to another site where Eric Thompson of Texas has tackled several Thanksgiving myths. I learned something from his site--I hadn't known of a First Thanksgiving claim of 1541 from Texas. Really, many states point to an early feast and prayer event and claim it was the earliest Thanksgiving, but the truth is, our holiday began when Lincoln made it a holiday during the Civil War. 

http://www.officespaceforrent.org/blog/6-myths-about-thanksgiving-revealed/