The map showing what the new Republic of Texas will look like shows West Virginia and Virginia separated. This did not happen until the beginning of the Civil War when a number of western counties ceded from Virginia to create West Virginia. This separation and the actual counties that ceded not have been predicted before it happened.
Throughout the film, they use pistols and rifles that did not exist at the time Texas entered the union.
Andrew Jackson's home is shown with some gas lighting in 1845, but that service was not established in Nashville until 1851.