Character mistake: Mattie attended a travelling Old West show in Memphis in which Rooster Cogburn was a performer. The flyer for the show shows the date of the show as July 18, 1903. The day of the show Mattie was told that Rooster died three days earlier (July 15, 1903). But Rooster's tombstone lists the date of his death as August 12, 1903. (01:41:55 - 01:43:35)
Character mistake: When Mattie is speaking to Rooster in the courthouse, she mentions her sister's name as Victoria. During her voice over of her letter to her mother, when she is riding out of Ft. Smith to catch up to Rooster she says "Kiss Violet on the cheek for me".