The document summarizes the origins and spread of the California Gold Rush in the late 1840s. It discusses how Lewis and Clark's expedition in 1804-1806 helped promote westward expansion. In 1848, gold was discovered in California, sparking the Gold Rush as thousands traveled there seeking fortune. There were three main routes for prospectors to take - overland across the plains, by ship around South America, or a mixed water and land route through Panama. Each route had advantages and challenges to consider.