What did john charles Fremont map out?

In the spring of 1842, John Charles was given orders from the Corps of Topographical Engineers to survey and map the emigrant route to Oregon known as the Oregon Trail. ... Frémont would complete his official orders and more, crossing into the Mexican province of California.

Explanation:

the dust bowl, otherwise known as the dirty thirties, was a huge dust storm that killed multiple (and i mean  multiple) farmer's crops, leaving them homeless, and foodless, and jobless. in california, there were 5.7 million residents, and the population shrank as mexicans were repatriated. however, when the dustbowl happened, a lot of people began to move to california. by 1940, 250,000 people had arrived. therefore, your answer would be  the population increased, massively.  i hope this !

explanation: