The discovery of gold in 1874 brought a flow of settlers into the Black Hills. Out of the gold rush grew cities, and other industries became apparent, such as lumbering, ranching and farming. John Brennan and Samuel Scott, along with a small party of men, came to the area in February 1876. They camped in what is now known as Cleghorn Springs, did some exploring, and decided to lay out the site of the present Rapid City. A square mile was measured off and the six blocks in the center were designated as a business section. Committees were appointed to bring in prospective merchants and their families to locate in the new settlement.
There was a steady influx of new families in the new community. Six months later, (in August 1876), over one hundred people called Rapid City their home.
When Rapid City was being built, the people resorted to nearby hills and chopped the logs of which the huts were constructed. The problems of life that confronted the pioneers of the 19th century demanded people of quick action and unflinching courage. It was the time when the elemental law of the "Survival of the Fittest" was in full sway. In those days, a man's horse was often the means of saving his life, and to steal one was considered as great a crime as murder. One of the earliest hangings in the Hills grew out of horse stealing, and the site on which this gruesome event took place is still a historical spot in Rapid City. On a day in June 1877, word got around through a group which had gone into the hills to obtain lumber, that there were either Indians or rustlers north of the settlement. Sheriff Moulton, first sheriff of Pennington County, and a posse set out for the Box Elder Creek region to hunt for the men. They found them asleep in a washout and brought them into town to investigate their possession of six unsaddled horses. Quick punishment was meted out to the horse thieves.
In February 1877, the cowboys gathered at the Colssum and Allen Store and decided to have a dance. It was strictly a stag affair. Bill Morris furnished the only music by playing his fiddle as he perched on the store counter.
According to some records, the first organized religion came to Rapid City in the form of the Union Aid Society in 1878, and later the Congregational Church joined them in 1879. However, we know that the earliest settlers got together on the Sabbath to worship and give thanks. Their meeting place was a crude log cabin structure. The first train to enter Rapid City was that of the Fremont, Elkhorn, and Missouri Valley (Chicago and Northwestern System). It arrived in 1886 and was greeted by a band of pranksters that staged a mock hold-up which was interrupted by the official welcoming committee.
Out of a campfire conversation in 1876 by a group of disheartened prospectors, the city of Rapid City was born. Named for spring-fed Rapid Creek which flows through the city, Rapid City has become a city with the fastest, steadiest growth rate in the state. Its population, as of 2007 was at 69,242, makes it the second largest in the state.