He was a founder and first president of the First Joint Stock Land Bank of Dayton, and also served as a high ranking business executive in New Orleans and later St. Louis for a number of notable companies, including Piggly Wiggly stores and Metropolitan Life Insurance.[3] Souers was called to active duty with the United States Navy on July 22, 1940, after serving eleven years in the naval reserves as an intelligence officer.[10] Souers was soon called back to Washington when president Truman appointed him to serve as Executive Secretary of the National Security Council following its creation on July 26, 1947.He was the first to brief Truman on the possible existence of a thermonuclear weapon, and remained a key figure in its development, being a major proponent of the establishment of an intelligence division within the Atomic Energy Commission.[3][13] Souers was awarded the Distinguished Service Medal by president Truman on December 2, 1952, for "keen foresight and tireless efforts toward fulfillment of a strong and effective security program".