Final answer:
The correct answer is option a. The phrase in question refers to the 'Gold Rush', specifically related to the California Gold Rush of 1848 where individuals sought quick riches through gold prospecting.
Step-by-step explanation:
The Gold Rush is the event referred to in the statement, where men desiring a feeling of fortune contributed to the hysteria. This can be identified through the provided context about the discovery of gold in California in 1848, which drew thousands to the West in search of quick riches.
The allure of gold sent many on wild chases, as mentioned, correlating with the historical phenomenon known as the California Gold Rush. The period was marked by dramatic shifts in population and the rapid accumulation of wealth for some, serving as an iconic element of American westward expansion and entrepreneurship during the 19th century.