Revealing mistake: When the 54th Mass. marches past a liberated plantation some black children wave them on. One of them is wearing a digital wristwatch.
Revealing mistake: In the scene after the battle of Agincort, where Henry and his retainers are walking meditatively among the heaps of the fallen, if you look carefully, you will see one of the fallen with his head raised watching the procession. He then realizes that he is on camera and puts his head back down. It's near the edge of the screen so may occasionally be cropped.
Continuity mistake: At the beginning of the movie (until Wasson's name appears in the credits), James Madison is writing on a paper copying from a large tome. Two people enter the room carrying a trunk. When he stands to go open the trunk and check its contents we can see that the book is gone from the desk. However, we see it again a minute later...when he picks it from those in the trunk and brings it to the desk. The first shot was a repurposed one. (00:00:50)