Shull was born at Fitzsimmons Army Hospital in Aurora, Colo., while his father was on joint assignment at Peterson Air Force Base. His father served for 30 years in the United States Army and spent more than 40 months in combat. Shull is a graduate of Heidelberg High School in Heidelberg, Germany. He earned a bachelor of science from the United States Military Academy in West Point, N.Y., where he was among the top 1 percent in leadership. Shull’s military schooling included Ranger and Airborne Schools. He holds a master of business administration from Harvard Business School, where he graduated with honors.
During his time in the Army, Shull served as Rifle Platoon Leader, Scout Platoon Leader, Support Platoon Leader, Company Executive Officer and Infantry Company Commander. He had numerous line and staff assignments, including serving as assistant professor at the U.S. Military Academy and commander of a Mechanized Infantry Company. Shull’s company was ranked No. 1 in combat readiness out of more than 30 others in the 4th Infantry Division. Shull earned several honors, including the Meritorious Service Medal, Expert Infantryman’s Badge, Ranger Tab and Airborne Wings.
In 1981, Shull was named to the 17th class of White House Fellows and served in the Office of the Chief of Staff. During his last active-duty assignment, then-Major Shull served as Military Assistant to Robert “Bud” McFarlane, Assistant to the President for National Security Affairs. During his time at the White House, Shull led a major re-evaluation and revision of White House management systems. He also conducted a comprehensive review of the National Security Council, was a Term Member of the Council on Foreign Relations and helped coordinate National Security Council low-intensity conflict policy initiatives. Shull represented the White House in helping to oversee the construction and dedication of the Vietnam Veterans Memorial. He earned the Defense Superior Service Medal.
Shull began his retail career in 1985 at Sanger-Harris, formed by Federated Department Stores, in Dallas, Texas, where he led business planning, training and recruiting. He served as Divisional Merchandise Manager of $20 million hard good businesses for the prominent regional 22-store chain.
From 1986 to 1990, Shull served as senior consultant at McKinsey & Co., where he directed defense/aerospace and retail client engagements to reduce costs and increase market share.