How did mining territories become states

Several territories in the west matured states when prospectors discovered gold or silver. These areas became boom towns which then matured as states due to a population boom. Mining encouraged the growth of Colorado, Arizona, the Dakotas, and Montana. After gold was found in Colorado in 1858 near Pikes Peak, workers hurried to the area. Many grieved and said the gold of Pikes Peak was a trick when in reality the Colorado mountains carried plenty of gold and silver. Much was ducked beneath the surface and difficult to extract.

d is the answer. leo should include the source.

determination