Answer:
Although westward expansion had been going on for a while before the discovery of gold, the Gold Rush increased the pace of that expansion. The Gold Rush led to tens of thousands of people trying to make it to California. So, the Gold Rush led to the railroads which led to a major boom in westward expansion.
Step-by-step explanation:
Westward expansion, the 19th-century movement of settlers into the American West, began with the Louisiana Purchase and was fueled by the Gold Rush, the Oregon Trail and a belief in "manifest destiny.