The settlement of Deadwood began illegally, on land which had been granted to the Lakota people in the 1868 Treaty of Fort Laramie. The treaty had guaranteed ownership of the Black Hills to the Lakota people, who considered this area to be sacred. The settlers' squatting led to numerous land disputes, several of which reached the U.S. Supreme Court.

Calamity later claimed she was so upset by Hickok's murder that she went after his killer with a meat cleaver, having left her guns at her residence. According to historical accounts, however, her story is more fiction than fact.

On September 26, 1879, a fire devastated Deadwood, destroying more than 300 buildings and consuming the belongings of many inhabitants. Many of the newly impoverished left town to start again elsewhere.

Deadwood's proximity to Lead often leads to the two cities' being collectively named "Lead-Deadwood".

On May 21, 1980, a raid by county, state, and federal agents on the town's three remaining brothels--"The White Door", "Pam's Purple Door", and "Dixie's Green Door"--accomplished, as one reporter put it, "what Marshal Hickok never would have done," and the houses of prostitution were padlocked.

Nearly 50 years after the first gold strike in the Black Hills, a local Deadwood man would reignite gold fever. John Perrett was panning in Potato Creek when he found a leg-shaped gold nugget. The lucky prospector became an instant Deadwood legend known as "Potato Creek Johnny".

Deadwood was the first small community in the U.S. to seek legal gambling revenues in order to maintain local historic assets. The state legislature legalized gambling in Deadwood in 1989, which rapidly generated new revenues and development.