Guess the Episode comes from 'No Exit'.
In this episode, Jo commented that Moyamensing Prison was built in 1835 and torn down in 1963. In truth, Moyamensing was constructed between 1832-1835, but was actually demolished in 1968.
One of the photographs on the table when Sam, Jo, and Dean are discussing Holmes is actually a photograph of Elizabeth Stride, one of the women generally accepted to have been murdered by Jack the Ripper.
Jo and Ellen's last name is Harvelle and the saloon is called Harvelle's Roadhouse. The word "roadhouse" had been the only part of the sign that was legible in episodes past.
Quote of the day:
Dean: Young girl got kidnapped by an evil cult.
Sam: Yeah, and does this girl have a name?
Dean: Katie Holmes.