After a two-year tour as a chartered accountant in England with Price Waterhouse & Company, Dyson was rewarded by being named a manager when he returned to the United States in 1938.
After the war, he returned to the business world as the Executive Vice President of Finance of the Textron Corporation under its founder, Royal (Roy) Little.
Dyson was recruited by the Federal government as a civilian to help set up the procurement and record keeping for the Lend Lease Program.
During his military service, the War Department assigned him to the Treasury Department to assist the Treasury Secretary, Henry Morgenthau Jr. and Secretary of State, Dean Acheson, at the United Nations Monetary and Financial Conference in Bretton Woods, New Hampshire.
The UNMFC was created to set the post-war exchange rates for world currencies, principally the dollar, franc, pound, and the German mark.