Timeline
By the Act of March 21, 1945, Congress permitted the President to appoint the Commandant of the Marine Corps to the grade of general. Alexander Vandegrift, then Commandant, was promoted from lieutenant general to general on April 4, 1945, to rank from March 21 of that year. He thus became the first Marine to serve in the grade of general. The Office of the Commandant was permanently fixed at the grade of four-star general under authority of the Act of August 7, 1947. All Commandants since that date have been entitled by law to serve in the grade of general and, in accordance with the provisions of 10 USC 5201, to retire in that grade.
In April 1969, the Senate passed and sent a bill to the White House that makes the Assistant Commandant of the Marine Corps a four-star general when the active duty strength of the Marine Corps exceeds 200,000. On May 5, 1969, President Richard Nixon signed the bill, and Lieutenant General Lewis William Walt was promoted to that rank on June 2, 1969, thus becoming the first Assistant Commandant of the Marine Corps to attain four-star rank. Legislation allowing the Assistant Commandant to wear the four-star insignia regardless of the strength of the Marine Corps was approved by President Gerald Ford on March 4, 1976.
On November 22, 1985, General George B. Crist was promoted to four-star rank and on November 27, he assumed the position of Commander in Chief of U.S. Central Command at MacDill Air Force Base, Florida. His appointment marked the first time a Marine headed a unified command and the first time the Corps had three four-star generals on active duty at the same time. Since 1985, a number of Marines have served in joint positions holding four-star rank, and it is no longer uncommon for the Corps to have four or five four-star generals on active duty at the same time.
In 2005, General Peter Pace became the first Marine to be appointed as Chairman of the Joint Chiefs of Staff, the chief military advisor to the President of the United States and most senior appointment in the United States armed forces. Previously, in 2001, General Pace was the first Marine officer to be appointed as Vice Chairman of the Joint Chiefs of Staff (VCJCS).
The standard tour length for the commandant (CMC) is four years; two years for the assistant commandant (ACMC); for a combatant commander, three years; and a total of four years served in consecutive two-year terms for the chairman and vice chairman of the Joint Chiefs of Staff (CJCS/VCJCS).
Read more about this topic: List Of United States Marine Corps Four-star Generals