Just before Russel gets hit by a tomahawk you can see him grimace before it even hits him.
During several action sequences, Davy Crockett's coonskin cap is seen to be of different coloration in consecutive shots, in some shots having a black banded area from front to back, but in shots immediately before or after, lacking this band. Also, the fluffiness of the fur varied from shot to shot. Obviously, several caps were used, even in individual action sequences.
When Davy visits Boston on his speaking tour, a banner appears that reads, "The Commonwealth of Boston Welcomes Hon. David Crockett." The state of Massachusetts, not the city of Boston, is called a "Commonwealth".
In several scenes throughout the movie, if you look at the muskets and pistols used, you will see that the flint striking the steel produces no smoke in the flash pan. This doesn't occur on the Long Rifles, as used by Crockett and Russell, as those pieces are live firing replicas. During the mid 1950's, reproductions of Springfield 1795, 1805 and 1812-1836 muskets and Harper's Ferry Rifles and military pistols were in very short supply. You will notice that these muskets are full infantry-length Springfield Trapdoor Rifles dressed up to look like flintlock muskets. Hollywood had to work with what they had. Modern film companies and prop houses have a vast supply of fully functional replicas, but in the 1950s that wasn't the case.
Throughout the battle sequences at the Alamo, the Mexican bayonets sometimes wobble, indicating they are made of rubber, rather than steel.
When Davy and George discover the Indians hiding in the bushes that had their land taken away from them by Bigfoot, keep an eye on the top left corner of the screen. You can see buildings and freeway traffic moving in the distance.
In his speech to the House of Representatives arguing against Jackson's expansion policies, Crockett uses the term "scalawags" twice. The term "scalawag" was not introduced until the 1840s, and was not widely used until after the Civil War, yet Crockett's speech was ostensibly between the years 1827 to 1835.
As the camera scans across the river from where Andy Jackson is camped near the beginning of the film, a modern house can be seen for a second or two.
When Red Stick gets away you can hear General Jackson groan but his lips don't move.
When Crockett arrives in western Tennessee, shown on a map, the geography of the scenes still shows east Tennessee mountains. In reality, the Obion River area around Rutherford, where Crockett went, is actually rather flat, river-bottom county, with small hills in comparison to the eastern mountains.
Davy and Polly's first born was John Crockett, second was Billy Crockett. Movie has Billy as the older, Johnny as the younger.