William Harding Jackson (March 25, 1901 – September 28, 1971) was a U.S. civilian administrator, New York lawyer, and investment banker who served as Deputy Director of the Central Intelligence Agency. Jackson also served briefly under President Dwight D. Eisenhower as Acting United States National Security Advisor from 1956 to 1957. Early life William Harding Jackson was born on March 25, 1901 on the Belle Meade Plantation, in Belle Meade, Tennessee near Nashville, Tennessee. He was named after his father William Harding Jackson (1874–1903), who died when he was two years old. His mother was Anne Davis Richardson (1877–1954). (After her husband's death, she married Maxwell Stevenson of Hempstead, New York). Jackson attended the Fay School in Boston and St. Mark's School, an Episcopal Preparatory school in Southborough, Massachusetts. He received his undergraduate Bachelor of Arts degree (B.A.) from Princeton University (1924) and his LL.B. from Harvard Law School (1928). Career In 1928, Jackson joined the New York law firm of Cadwalader, Wickersham & Taft. In 1929 he became an Associate of Beekman, Bogue & Clark. Following the stock market crash of 1929, Jackson moved to the business and financial interest law firm of Carter, Ledyard & Milburn, where he became a full partner in 1934. During World War II, Jackson served in the United States Army (6 March 1942 – 7 July 1945) as an intelligence officer, graduating from the Army-Air Force (USAAF) Air Combat Intelligence School at Harrisburg, Pennsylvania. He was assigned as an A-2 Assistant Intelligence officer, HQ 1st Bomber Command at 90 Church Street in New York (close to his law office), which immediately became the USAAF Anti-Submarine Command. Jackson was the principal author (along with investment banker Alexander Standish and Harold B. Ingersoll) of the USAAF Bay of Biscay Intelligence Estimate, calling for the attack on Nazi U-boats at their source on the coast of France. This was a significant turning point for the Battle of the Atlantic. After graduation from Harrisburg in June 1942, Jackson was promoted to Major and brought into the War Department by Secretary Henry L. Stimson, where he became General Staff (Chief of Secret Intelligence reporting to General George C. Marshall from the European Theater of Operations (ETO) at COSSAC headquarters) with the cover title Chief of G-2 intelligence for 1st Army Group (FUSAG). After training on the Enigma codes at Bletchley Park, UK, he became the senior ULTRA SCIU