How did the Goldrush contribute to the motivations of Westward Expansion?

The gold rush propelled the expansion and settlement of the western United States on a massive scale. ... This action led to Mexico to declare war on the United States, starting the Mexican-American War. forty-niners: people, especially prospectors, who went to California in 1849 during the gold rush.

the answer is either c or d i think its d

the historians cited in the article all agree with one another about the cause of the civil war. despite coming from different backgrounds and cultures, the historians agree that slavery was the root cause of the civil war. the fact that all these historiansgenerally agree with one another makes their shared viewpoints more reliable and valid, especially because the historians have different backgrounds and all work for the well-respected institutions of howard university, clemson university, and the university of colorado.