As depicted in the show, many iconic frontier folk heroes such as Wild Bill Hickock, Calamity Jane, and Wyatt Earp spent time in Deadwood (and one of them even died there). The two lead characters of the series, Seth Bullock (Timothy Olyphant) and Al Swearengen (Ian McShane), are also based on real people.

Death, the Chinese Exclusion Act, fewer economic opportunities, and a desire to return to their homeland all affected the declining population of the Chinatown in Deadwood. Ching Ong is said to have been "the last Chinese individual to have left the town in 1931 after having lived there for over 45 years."

Keone Young is an Asian-American actor who is known for playing Mr. Wu from Deadwood and voicing Kaz Harada from Hi Hi Puffy AmiYumi. He also acted in Men in Black 3, Samurai Jack, Kung Fu Panda: Legends of Awesomeness, Codename: Kids Next Door, The Mighty B, American Dragon: Jake Long and the Spider-Man 3 video game.

In a symbol of loyalty to Swearengen, Wu slices off his braid (an action punishable by death in China at the time) and declares he will remain in America forever. In Season 3, he returns from business in San Francisco wearing Western dress (which, as multiple characters remark, he looks terrible in).