The set of Deadwood's Main Street was reused with very little alterations for Django Unchained (2012) and Westworld (2016).
The set of Deadwood was built to be as functional and realistic as possible, and was so detailed it even featured period-appropriate items in drawers. Production designer Maria Caso was nominated for an Emmy for Outstanding Art Direction for all three seasons, winning for the second.
When David Milch created Deadwood he originally wrote the character of Al Swearengen specifically for Ed O'Neill (Al Bundy, Married... with Children (1987)). But HBO insisted on using a different actor.
In this hour long pilot episode the word "fuck" is heard 51 times.
The real Al Swearengen was born and raised in Chicago. After Ian McShane was cast, David Milch altered the character's back story so that he was born in England and moved to Chicago in his youth, in case sharp observers noticed any trace of an English accent in McShane's performance.