The series is set in the 1880s, yet a character is described as moving to Ponca City, which was not founded until after the Cherokee Strip Land Rush of 1893.
Frank mentions Burma Shave which was not marketed till 1925.
In the song in the saloon they make reference to nicotine being addictive. Addiction to nicotine was first researched in the 1900s and only proved in the 1970s.
Frank tells a young Roy 'fuzz looks good on a peach not on a man' and says this is from a Burma-Shave sign. Burma-Shave was first introduced in 1925 while the show is set in the 1870-80s.
Frank Griffin makes a reference to Burma Shave while introducing Roy Goode to his crew. The show is set in the 1880s, but Burma Shave wasn't introduced until 1925.