Born in Sioux City, Iowa, Countryman attended Pierson High School.

During World War II, Countryman served in the United States Army Air Forces as a pilot and was commissioned lieutenant colonel.

From 1950 to 1954, Countryman served as attorney for Story County, Iowa as a member of the Republican party.

In 1956, 1960, and 1968, Countryman unsuccessfully sought the Republican nomination for United States Senate.

He continued to practice law in Nevada, Iowa and also managed his farms.