When Jess is grazed by a Rebel bullet, the cut runs across his forehead. In the next scene, the cut runs up and down.
When Jess places the butt of the rifle on the ground after letting the Confederate soldier go, the trigger is on the side closest to him in the long shot. In the close shot, the trigger is on the side of the rifle away from him.
During the final battle, a Confederate wagon flips over near the water bank. As the battle continues, the wagon has disappeared.
At approximately 1:28, right after Josh and Jess have a conversation about dying, Jess is seen in a long shot using a scythe to cut a field. He stops, flips it end-for-end, and grabs the blade end in his hand, wrapped around the blade, while he reaches into his pocket for a file. No farmer worth his salt who valued his fingers would hold a scythe by the blade in that manner. Even if dulled a bit from cutting it would still be sharp enough to slash through skin quite easily.
The story is set in 1862, one year after the Civil War began. At the service in the Quaker meetinghouse, the Union Army officer asks for volunteers and says that the war has been going on for two years.
Several times during the film, people try out the new organ, although no one pumps the organ and there is no evidence of electric power in the house.
When Josh leaves the house to fight, he carries what appears to be a rolling block, breech-loading, single shot rifle that wasn't designed until the mid-1860s. It changes to a muzzle loader at the battle.
When the two Rebel scouts come upon the creek, and one of them rides into the water, the light from a reflector panel becomes clearly visible across his face.
The Minneapolis steam engine at the fair is too new for the Civil War era.
When the Hudspeth girls are serenading Jess and Josh in the cabin, neither of the instruments being played match the music that is heard.
When Jess Birdwell sends the children upstairs after mother Eliza retires to the barn, he says, "up stairs to bed, all of thee!" In Quaker dialect, the pronoun thee is used as the objective case of thou, and is used only when addressing an individual. He should have said, "up stairs to bed, all of you!"