In the bar scene where Nate shows off his powers, P. T. Barnum buys a round for everybody. In real life, P. T. Barnum was a speaker for the temperance movement, i.e., he spoke in favor of abstaining from alcohol. He earned a living in this manner in the wake of bad investments circa 1850.
The type of colorful latex balloons shown did not exist in 1870.
The nickel plated revolver PT Barnum had did not exist in 1870.
Tranquilizer dart gun was not invented until 1950s.