When Jake is preparing to go to bed after his marriage and is talking with Daniel Holt he removes his left boot three times.
A wooden country revival style "teddy bear" is seen in "Aunt Wilma's" parlor. The distinctive "teddy bear" was created in honor of Teddy Roosevelt, decades later, however toy wooden bears were common items even before the Civil War. The story of "Goldilocks and the Three Bears" was written in 1834, greatly increasing interest in toy bears. Stuffed bear toys started showing up in catalogs as early as 1894, long before Teddy Roosevelt was associated with them.
When Jake complains of losing the upper-half of his pinky finger, the brace holding down the top joints of the actor's finger is briefly shown as the camera pulls in on his hand.
Seeing exposed bullets in a pistol's chambers is normal for the American Civil War era. Pre-rolled paper cartridges were introduced long before the Civil War and were widely used for cap and ball pistols. In the interest of loading quickly, they were rarely covered with lard or another wad. Therefore seeing the "naked" bullet in a pistol's chambers is perfectly accurate from an historical perspective.
In the very last scene, as Holt is riding away you can see three flashes of light in the sky - landing lights from planes circling a nearby airport.
Civil-war era skirts did not have even one in-seam pocket, let alone two. Fancy Chatelaines were used to hold purses and other items by the wealthier women, and the poorer classes made do with cloth pockets suspended from a strap that was pinned to the waistband. Flat surface pockets came in after the closing of the civil war.
After German boy is told his father was killed, there is a brief scene of a woman standing in a doorway. The door has modern day machine-made lace.