the Mississippi River. The boom times attracted millionaires and their mansions, as well as hustlers, poverty, and crime. Denver gained regional notoriety with its range of bawdy houses, from the sumptuous quarters of renowned madams to the squalid "cribs" located a few blocks away. Business was good; visitors spent lavishly, then left town. As long as madams conducted their business discreetly, and "crib girls" did not advertise their availability too crudely, authorities took their bribes and looked the other way. Occasional cleanups and crack downs satisfied the demands for reform. With its giant mountain of copper, Butte, Montana, was the largest, richest, and rowdiest mining camp on the frontier. It was an ethnic stronghold, with the Irish Catholics in control of politics and of the best jobs at the leading mining corporation Anaconda Copper. City boosters opened a public library in 1894. Ring argues that the library was originally a mechanism of social control, "an antidote to the miners' proclivity for drinking, whoring, and gambling". It was also designed to promote middle-class values and to convince Easterners that Butte was a cultivated city. Race and ethnicity European immigrants European immigrants often built communities of similar religious and ethnic backgrounds. For example, many Finns went to Minnesota and Michigan, Swedes and Norwegians to Minnesota and the Dakotas, Irish to railroad centers along the transcontinental lines, Volga Germans to North Dakota, and German Jews to Portland, Oregon. African Americans African Americans moved West as soldiers, as well as cowboys, farmhands, saloon workers, cooks, and outlaws. The Buffalo Soldiers were soldiers in the all-black 9th and 10th Cavalry regiments, and 24th and 25th Infantry Regiments of the U.S. Army. They had white officers and served in numerous western forts. About 4,000 black people came to California in Gold Rush days. In 1879, after the end of Reconstruction in the South, several thousand Freedmen moved from Southern states to Kansas. Known as the Exodusters, they were lured by the prospect of good, cheap Homestead Law land and better treatment. The all-black town of Nicodemus, Kansas, which was founded in 1877, was an organized settlement that predates the Exodusters but is often associated with them. Asians The California Gold Rush included thousands of Mexican and Chinese arrivals. Chinese migrants, many of whom were impoverished peasants, provided the major part of the workforce for the building of the Central Pacific portion of the transcontinental railroad. Most