In the scene where Robert first sees Eveline the bodice of the dress has very thin, synthetic looking material (authentic materials are MUCH heavier) and it appears to be the middle of the day (off-shoulder gowns were not worn until evening/night by anyone of marrying age).
Eveline's hair should not have been down in a short braid with a colored hair-band at the end. Women of that time typically had their hair twisted up at the nape of their neck and, also, were very conscious that the piece (snood or similar) that is holding up their hair is of the same color as their hair.
8 minutes into the movie, right after a skirmish, Robert sees a Yankee officer face down on the ground. On his left arm is a wristwatch, It shines so brightly one wonders how the editors missed it.
When Eveline is shown from behind, "playing" the piano, she does not play far enough down on the piano to coordinate with the low notes we hear.