The first humans certainly had an advantage with regards to finding precious materials such as gold and silver. It's easy to imagine flakes or small nuggets of gold naturally exposed by streams and lakes. Human beings walking around the area could easily collect them for trade or utility.

As time went on, more and more of the easily available precious metals and gems were picked. Miners continued their search deeper and deeper into the earth, risking their lives and wealth in search for these valuable materials.

With the expansion of human civilization to new lands and continents, new sources were found. In 1849, gold was found in a stream near Coloma, California. After the news broke, hundreds of thousands of miners, called the 49ers, rushed out to California in search of the gold.

Within a few years, most of the easily found gold was picked, driving the miners to use more advanced techniques. By the mid 1850s, the miners had adopted hydraulic mining equipment and other mechanical...