Editing Black Hawk, Colorado (section)

===Mining boom===
[[File:Black Hawk, Colorado (1864).jpg|thumb|left|Black Hawk, 1864]]
In May 1859 the discovery of gold in Gregory Gulch by its namesake, John H. Gregory, brought thousands of prospectors and miners into the area, combing the hills for more gold veins. The Bobtail [[lode]] was discovered the following month.<ref name = "Sims"/> The [[Slave states and free states|free]] [[Territory of Colorado]] was organized on February 28, 1861.<ref name="Colorado Origin Act">{{cite web|url=https://www.loc.gov/law/help/statutes-at-large/36th-congress/session-2/c36s2ch59.pdf|title=An Act To provide a temporary Government for the Territory of Colorado|author=Thirty-sixth United States Congress|website=[[Library of Congress]]|author-link=36th United States Congress|date=February 28, 1861|access-date=December 24, 2024}}</ref> The Black Hawk Point, Colorado Territory, post office opened on December 6, 1862.<ref name=CPO>{{cite book|title=Colorado Post Offices 1859–1989|first1=William H.|last1=Bauer|first2=James L.|last2=Ozment|first3=John H.|last3=Willard|date=1990|publisher=[[Colorado Railroad Museum|Colorado Railroad Historical Foundation]]|location=[[Golden, Colorado]]|isbn=0-918654-42-4}}</ref> Hardrock mining boomed for a few years, but then declined in the mid-1860s as the miners exhausted the shallow parts of the veins that contained free gold and found that their [[Amalgam (chemistry)#Gold amalgam|amalgamation]] mills could not recover gold from the deeper sulfide ores.<ref>A. H. Koschman and M. H. Bergendahl (1968) ''Principal Gold-Producing Districts of the United States'', US Geological Survey, Professional Paper 610, p.86.</ref>

[[Nathaniel P. Hill]] built Colorado's first successful ore [[smelter]] in Black Hawk in 1868. Hill's smelter could recover gold from the sulfide ores, an achievement that saved hardrock mining in Black Hawk, Central City, and [[Idaho Springs, Colorado|Idaho Springs]] from ruin. Other smelters were built nearby. Black Hawk's advantageous location on North Clear Creek made it the center of ore processing for the area, and it became known as the "City of Mills".<ref>James E. Fell, Jr. (1979) ''Ores to Metals'', Lincoln: Univ. Nebraska Press, pp. 27-54.</ref> The name of the Black Hawk Point post office was shortened to Black Hawk on February 8, 1871.

The [[Colorado Central Railroad]] extended its line to the town in 1872.<ref name="Sims">Paul K. Sims and others (1963), ''Economic Geology of the Central City District, Gilpin County, Colorado'', US Geological Survey, Professional Paper 359, p.7-8.</ref> Colorado became a state on August 1, 1876,<ref name=Colorado_Statehood_Proclamation>{{cite web |url=https://www.presidency.ucsb.edu/documents/proclamation-230-admission-colorado-into-the-union|title=Proclamation 230—Admission of Colorado into the Union|author=[[Ulysses S. Grant]] |date=August 1, 1876|publisher=The American Presidency Project|access-date=December 24, 2024}}</ref> and the City of Black Hawk was incorporated on June 12, 1886.<ref name=MuniIncCO/> The spelling of the Black Hawk post office was changed to Blackhawk on January 30, 1895, but was then changed back to Black Hawk on July 1, 1950. Black Hawk is currently the least populous city in the State of Colorado.<ref name=Census>{{cite web|url=https://www.census.gov/quickfacts/fact/dashboard/CO/|title=QuickFacts for Colorado|publisher=[[United States Census Bureau]]|access-date=December 24, 2024}}</ref>

A restored narrow-gauge railroad depot and locomotive are on display on the east side of downtown. Black Hawk was also served by the two-foot-gauge [[Gilpin Tramway]] which climbed from Black Hawk to the mines above Central City.