The United States Army Reserve (USAR) is a reserve force of the United States Army. Together, the Army Reserve and the Army National Guard constitute the Army element of the reserve components of the United States Armed Forces. Since July 2020, the Chief of the United States Army Reserve is Lieutenant General Jody J. Daniels. The senior enlisted leader of the Army Reserve is Command Sergeant Major Andrew J. Lombardo. History Origins On 23 April 1908 Congress created the Medical Reserve Corps, the official predecessor of the Army Reserve. After World War I, under the National Defense Act of 1920, Congress reorganized the U.S. land forces by authorizing a Regular Army, a National Guard and an Organized Reserve (Officers Reserve Corps and Enlisted Reserve Corps) of unrestricted size, which later became the Army Reserve. This organization provided a peacetime pool of trained Reserve officers and enlisted men for use in war. The Organized Reserve included the Officers Reserve Corps, Enlisted Reserve Corps and Reserve Officers' Training Corps (ROTC). Interwar period and World War II The Organized Reserve infantry divisions raised immediately after World War I generally continued the lineage and geographic area distribution of National Army divisions that had served in the war. They were maintained on paper with all of their officers and one-third of their enlisted men. Units in other arms of the Army besides infantry, most notably cavalry, field artillery and engineers were also formed. Organized Reserve units sometimes maintained relationships with one or several colleges or universities in close proximity, which populated them with officers through the ROTC. Service in the Organized Reserve during the interwar period was not as appealing as the Army expected, and suffered because of limited funding that restricted training opportunities. Most divisions reached their full complement of officers, but had less than 100 enlisted men, since there was no incentive for them to serve. The extent of prewar mobilization--"a state neither of war nor of peace"--disrupted the Organized Reserve, and officers were called to active duty individually beginning in 1940 and assigned to Regular Army and National Guard units. When the Organized Reserve was nominally mobilized via presidential order beginning in 1942, "few of the Reserve officers originally assigned to...units were available for duty with them. Consequently, the units as activated bore small resemblance to those of peacetime." The order and timetable in which the Organized Reserve divisions were ordered to