Stars who served in the military

Alan Alda, who played Hawkeye Pierce in the classic TV series "M*A*S*H," joined the Army Reserve after graduating from Fordham University. He completed a six-month tour of duty during the Korean War.

Keep clicking to see other stars who served in the military.

Rob Riggle

Rob Riggle told CBSNews.com of his time in the Marines: "I was an undergrad a the University of Kansas, and I had my pilot's license when I was an undergrad. I was also a theater and film major. So I either was going to be 'Top Gun' when I graduated or I was gonna be a waiter. And I thought being 'Top Gun' sounded much sexier, much cooler. And so I did -- I went through officer's candidate school, went through flight school and the further I got along, the more I realized if I continue flying I'm not gonna be able to pursue my dream of comedy and acting. So I stopped flying, became a ground officer, had a short contract, fulfilled my contract and pursued comedy and acting. I stayed in the reserves though and did the reserves for the last 14 years. And I just retired in January from the Marines. This is a great country, you can do it all."

Drew Lachey

"I went right into the Army out of high school and signed up to be a medic," Drew Lachey told CBSNews.com. "I did my basic training in Fort Leonard Wood, Mo., and then I did medic training in Fort Sam Houston and then I transferred to a field hospital in Fort Totten in Flushing, Queens. My girlfriend at the time -- now my wife -- was dancing at the time in New York. So I did that for a while, I drove an ambulance for a while in the city while I was doing my reserves. Then I got the call to be in a boy band and that's when my life changed."

"It taught me a lot of life lessons, a lot of humility, discipline, stronger work ethic -- all great stuff," he added.

Hugh Hefner

Playboy founder Hugh Hefner joined the Army as an infantry clerk after graduating from high school in 1944. While there, he contributed cartoons for Army newspapers. He was honorably discharged in 1946.

Elvis Presley

Elvis Presley took a break from stardom when he received his draft notice in 1957 and joined the Army the following March. He was stationed in Texas and later served in Germany (where he met future wife Priscilla Presley), getting promoted to sergeant before leaving the service in 1960.

Bill Cosby

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Bill Cosby enlisted in the Navy in 1956. He trained as a hospital corpsman and served aboard ships and at the Marine base at Quantico, Va., before being sent to Bethesda Naval Hospital. He was honorably discharged in 1960.

Drew Carey

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After leaving Kent State University in 1980, Drew Carey enlisted into the United States Marine Corps Reserve and served for six years.

Tony Bennett

Tony Bennett was drafted into the Army in 1944 during the final stages of World War II, and served in Germany and France. Upon his discharge and return to the U.S. in 1946, he studied at the American Theater Wing on the GI Bill.

Yogi Berra

Yogi Berra (then baseball hopeful Lawrence Peter Berra) joined the Navy in 1943, after he turned 18. Trained as a gunner's mate, he worked on a rocket launching boat and served on D-Day during World War II.

Chuck Norris

Chuck Norris joined the Air Force in 1958, and began studying martial arts stationed at the Osan Air Base in South Korea. He received the Veteran of the Year award from the Air Force in 2001.

Jimi Hendrix

Jimi Hendrix enlisted in the Army in 1961 and was assigned to the 101st Airborne Division, where he was stationed at Fort Campbell in Kentucky. He served until 1962, when he was discharged due to an injury.

Clint Eastwood

Clint Eastwood was drafted into the Army during Korean War and assigned to Fort Ord in California, where he served as a lifeguard.

Ice-T

Ice-T, born Tracy Marrow, joined the Army after high school to support his girlfriend and daughter. He served four years in the 25th Infantry Division, based in Hawaii.

Leonard Nimoy

Leonard Nimoy enlisted in the Army Reserve in 1953 and served a total of 18 months. He spent most of his time at Ft. McPherson in Georgia, and was discharged in 1955 having earned the rank of sergeant.

Mel Brooks

Mel Brooks (then Melvin Kaminsky) joined the Army during World War II as a combat engineer. One of his tasks during the war was to diffuse land mines, and he also fought in the Battle of the Bulge.

Morgan Freeman

After graduating high school in 1955, Morgan Freeman turned down a partial drama scholarship from Jackson State University and opted to join the Air Force, where he served as a radar technician. He left the Air Force in 1959.

George Carlin

In 1954, at age 17, George Carlin enlisted in the Air Force, where he was trained as a radar technician and stationed in Louisiana. He was court martialed three times before later receiving a general discharge in 1957.

Willie Nelson

Willie Nelson went into the Air Force after graduating high school in 1950, but only served about nine months before his was medically discharged because of back problems.

MC Hammer

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MC Hammer (born Stanley Kirk Burrell) joined the Navy after a brief stint in college, and spent three years as an aviation storekeeper.

Gene Hackman

Gene Hackman dropped out of high school at the age of 16 to join the Marines, lying about his age in order to enlist. He worked as a radio operator and finished his high school education before being discharged in 1951.

Jimmy Stewart

Jimmy Stewart (seen here in "Mr. Smith Goes to Washington") was drafted into the Army in 1940 but was rejected because he was underweight for his height. He worked with colleagues to put on the necessary pounds, and successfully enlisted with the Air Corps in 1941. After World War II, he remained in the Air Force Reserve and was promoted to brigadier general in 1959. He retired from the Air Force in 1968.

Clark Gable

Clark Gable was already an established movie star when he joined the military. Devastated after his third wife, Carole Lombard, died in a 1942 plane crash, he enlisted in the Army Air Force at the age of 41. He served as a tail-gunner on five bombing missions over Germany and made a propaganda film for the Army before being discharged in 1944.

Henry Fonda

Henry Fonda served in the Navy during World War II, saying, "I don't want to be in a fake war in a studio." He was awarded the Navy Presidential Unit Citation and the Bronze Star.

Humphrey Bogart

Humphrey Bogart enlisted in the Navy in the spring in 1918, during World War I. He spent most of his months in the navy after the war ended, ferrying troops back from Europe. The star may have received the trademark scar on his upper lip during his naval service – though the actual circumstances of how he got it are unclear.

James Earl Jones

James Earl Jones will return to the "Lion King" franchise.

Oliver Stone

Oliver Stone joined the Army in April 1967, specifically requesting combat duty. He served in Vietnam from September 1967 to November 1968, first with the 25th Infantry Division and later the 1st Cavalry Division. He was wounded twice during his 15 months of duty and received two personal awards: a Bronze Star with "V" device for heroism in ground combat, and a Purple Heart with an Oak Leaf Cluster.

Johnny Carson

Johnny Carson enlisted in the Navy on June 8, 1943, as an apprentice seaman. Commissioned an ensign late in World War II, Carson was assigned to the USS Pennsylvania in the Pacific and was en route to the combat zone aboard a troop ship when the bombing of Hiroshima and Nagasaki ended the war. He later served as a communications officer in charge of decoding encrypted messages.

Mr. T

After getting expelled from Prairie View A&M University after one year, Mr. T (Laurence Tureaud) enlisted in the Army in the mid-1970s and served in the Military Police Corps. In November 1975, he was awarded a letter of recommendation by his drill sergeant and was also promoted to squad leader.

Gene Wilder

Gene Wilder was drafted into the Army in 1956 and served for two years, during which time he worked as a medic in Pennsylvania.

Ernest Borgnine

Ernest Borgnine joined the Navy as an apprentice seaman in 1935, after graduating from high school. He was discharged in 1941, but re-enlisted after Pearl Harbor and served until 1945, reaching the rank of gunner's mate first class.

Sources: Biography.com, Marines magazine, Military.com, Naval History and Heritage Command, National Museum of the U.S. Air Force, Parade.com, Variety.com, U.S. Army Corp. of Engineers