Miller owned a car dealership and a general store before entering politics.
[1] From the years of 1917 to 1926 Miller's business required him to live in Cedar Rapids, Iowa.
At this job, miller has been recognized as the only man who shipped automobiles by the train load into the state of Iowa.
Miller had also managed a general store in Morley, Iowa for almost fourteen years.
Miller can be accredited for building up and what still remains as one of the largest herd of pure bred Aberdeen Angus cattle in the world on top of being the largest individual farmer in Jones or Cedar counties.