C.A. "Mack" McKinney, 80, a Marine veteran of three wars who became a Capitol Hill advocate for the enlisted military, died of complications from cancer Nov. 15 at Inova Alexandria Hospital. He lived in Alexandria.

Sgt. Maj. McKinney, who served nearly 30 years in the Marine Corps, spent 34 years after his military service as a representative for veterans organizations, becoming one of the best-known military lobbyists working Congress.

He played a decisive role in virtually every significant piece of legislation affecting compensation and benefits for active, reserve, Guard and retired enlisted service members, according to the citation for the Defense Department's Medal for Distinguished Public Service, which he won in 2004.

He was credited with helping stem the losses of mid-career military personnel by persuading leaders of the Senate and House Armed Services committees to authorize two consecutive double-digit pay raises during the late 1970s. As legislative director of the Non Commissioned Officers Association from 1972 to 1992 and a volunteer for the Marine Corps League, he also worked to improve separation pay for enlisted personnel, make improvements in military spouses' survivor benefits and extend loans for veterans who buy second homes.

The Navy Times cited him in 2000 as the person most responsible for a pay raise awarded that year to enlisted soldiers, sailors and Marines. The article noted that in the mid-1980s, Sgt. Maj. McKinney helped increase hazardous duty pay for enlisted members to a level on par with raises given to officers. His most successful argument was that "if a lieutenant is jumping out of airplane, there was probably a sergeant behind him pushing."

He spoke more than 100 times before Congress.

In 1985, Sgt. Maj. McKinney formed the Military Coalition, a consortium that, among other accomplishments, successfully opposed legislation that would have stopped cost-of-living increases for retirees for seven years. He later served as co-chairman, coordinator and administrator of the organization, which now includes 36 groups. The Non Commissioned Officers Association named an award in his honor.

For the past 10 years, Sgt. Maj. McKinney was legislative counsel to the Fleet Reserve Association.

An Indiana native, he joined the Marine Corps in 1942 and served in the invasions of the Marshall Islands and Okinawa during World War II. He also served in the Korean War and in the response to the Tet Offensive during the Vietnam War. He retired from military service in 1971 after 29 years and six months because, he joked, "I didn't want to make it a career."

Sgt. Maj. McKinney was appointed to the Veterans Administration Committee on Cemeteries and Memorials, serving from 1987 to 1993.

He was also the first recipient of the Marine Corps League's Gunnery Sergeant John Basilone Award and was honored by the U.S. Coast Guard with the Meritorious Public Service Award.

Sgt. Maj. McKinney was a founding member and president emeritus of the Exchange Club of Capitol Hill. He was in the Veterans of Foreign Wars, Disabled American Veterans, 1st and 3rd Marine Division associations, Marine Corps Aviation Association, Congressional Marines, Marine Corps Law Enforcement Foundation, Marine Corps Heritage Foundation and the Marine Corps Association. He was also a charter member and second president of the Combined National Veterans Association of America.

Survivors include his wife of 52 years, Rosemarie Swinford McKinney of Alexandria; three children, Lee Quancelino of Brawley, Calif., Michael McKinney of Fairfax and Jaqueline Enge of Kennewick, Wash.; six grandchildren; and two great-grandchildren.

As a military lobbyist, C.A. "Mack" McKinney, 80, influenced legislation on compensation and benefits.