The character of Robert Bell was inspired by Theodore Judah, architect of the Transcontinental Railroad and first chief engineer of the Central Pacific. Judah led an expedition that determined the best route for the railroad and presented his survey to President Buchanan. The actual approval for federal funding though would come from the next president, Abraham Lincoln.
This episode stars Tom Noonan and Ted Levine, both of whom have played villains in a Hannibal Lecter film. Noonan played Francis Dollarhyde (aka The Tooth Fairy) in Manhunter (1986), with Brian Cox as Lecter, and Levine played Jame Gumb (aka Buffalo Bill) in The Silence of the Lambs (1991) with Anthony Hopkins as Lecter.
Daniel Johnson (railroad foreman) said before the war he was a Copperhead. The Copperheads, also called the Peace Democrats, were a faction of the Union's Democratic Party who opposed the Civil War and called for an immediate peace settlement with the Confederacy. They would have rather the Confederacy been allowed to seceded and become its own nation rather than go to war, they opposed the draft, encouraged desertion and viewed President Lincoln as a tyrant. As such their nickname of Copperhead was given to them by Republicans, the name referring to the Eastern Copperhead, a venomous snake.
Sean and Mickey McGinnes are showing a "Magic Picture Show" that involved projecting images of color photographs onto a screen. At this time color photography was a brand new science and art, most people in 1865 had never seen a color photograph. The first color photo was taken by Thomas Sutton in 1861, using a method developed by Scottish physicist James Clerk Maxwell in 1855. Maxwell's method was called the Three-color Process, which involved taking three separate monochrome pictures, one using a red filter, the second a blue filter and the third a green filter, and then by superimposing the three images together and altering the proportions of each color all of the visible colors could be recreated, as red, green and blue are the three prominent primary colors.
Anson Mount's (Cullen Bohannon) great-great-great grandfather was a Colonel in the Confederate Calvary during the Civil War.