He apprenticed a printer before moving to Iowa to work with a lawyer, and was admitted to the, where he briefly employed himself as a gold prospector, and later as a mule train driver.
He apprenticed a printer before moving to Iowa to work with a lawyer, and was admitted to the Iowa Bar. In July 1849, Johnson left Iowa for the Gold Rush in California, where he briefly employed himself as a gold prospector, and later as a mule train driver.