Final answer:
California and Nevada experienced major gold and silver strikes, with the California Gold Rush in 1848 and the discovery of the Comstock Lode in Nevada in 1859.
Step-by-step explanation:
The states that saw major gold and silver strikes are California and Nevada. The discovery of gold at John Sutter's sawmill in northern California in 1848 kicked off the California Gold Rush, leading to an influx of prospectors known as Forty-Niners. In Nevada, the Comstock Lode was discovered by Henry T. P. Comstock in 1859, amounting to the first significant silver find in the United States. This discovery resulted in $300 million worth of silver being extracted from shafts that reached hundreds of feet into the mountain, significantly contributing to the state's wealth at that time.