After his discharge, Harvey returned to Rusk County and farmed for a year, but the failure of the crop forced him to sell the land. He became a railway
postal clerk in 1920. From 1923 to 1926, Harvey worked as chief clerk in
San Antonio, Texas, and in 1926 he began working for the
Bureau of Internal Revenue Intelligence Unit, handling fraud investigations. In the course of auditing oil business, Harvey became well versed in the then new industry. He invested in a percentage of a 36-acre patch in the
East Texas Oil Field. Many of his subsequent prospects failed, but notable successes included patches in the East Long Lake field in
Anderson County, Texas, and the
Spraberry Trend near
Midland, Texas. ==World War II==