In what year did Dr. Mark T. Esper assume the role of Secretary of Defense?

Dr. Mark T. Esper became the Secretary of Defense on July 23, 2019. His appointment followed a period of transition within the Department of Defense, and he succeeded Patrick Shanahan in this vital leadership role. Before becoming Secretary of Defense, Esper had a significant background, including serving as the Secretary of the Army, which equipped him with valuable experience in military and defense matters. His tenure focused on various critical issues, including military readiness, strategic competition with rival nations, and reforming the Pentagon's bureaucracy. Understanding this timeline is essential for grasping the changes in leadership within the Department of Defense and the context of U.S. military policy during that period.