A third-generation Washingtonian, Major O'Laughlin graduated from Gonzaga College High School. After receiving a degree from the University of Notre Dame, he enlisted in the Marine Corps in 1942. As a Marine Captain, he was a Company Commander with the 1st Marine Division in the South Pacific. He fought in the Ryukyu Islands and was wounded in battle on Okinawa on May 5, 1945, the day after his 24th birthday. He was awarded the Silver Star and the Purple Heart, among other citations.

Major O'Laughlin returned to Washington after the war and, while stationed at Quantico Marine Base, attended Georgetown University law school at night, receiving his degree in 1952. He left the Marine Corps with the rank of Major in 1954.

He practiced law in Washington for 50 years, working largely as a sole practitioner. He specialized in civil law and continued his practice until his death.

He was a longtime member of the Shrine of the Most Blessed Sacrament Catholic Church in the District, the American Legion and several fraternal organizations.

His first wife, Anne Handley O'Laughlin, died in 1968 after 21 years of marriage. A stepdaughter, Karen Crissman, died in 1982.

Survivors include his wife of 33 years, Ethel Alivani O'Laughlin of Chevy Chase; three children from his first marriage, Maureen Irani of Bethesda, Joan Gallagher of Potomac and John O'Laughlin of Cabin John; a stepdaughter, Gail Kelly of Groton, Conn.; 10 grandchildren; and three great-grandchildren.

On Saturday, May 22, 2004. The beloved husband of Ethel A. O'Laughlin and the late Anne H. O'Laughlin; father of Maureen Irani, Joan Gallagher, John O'Laughlin and step-daughter Gail Kelly; brother of the late Rev. Charles John O'Laughlin. He is also survived by 10 grandchildren and three great-grandchildren.

Mass of Christian Burial will be offered on Wednesday, May 26, 2004 at 11 a.m. from the Shrine of the Most Blessed Sacrament, 6001 Western Ave. N.W., Washington, D.C. Interment Arlington National Cemetery on Wednesday, June 16, at 1 p.m.

In lieu of flowers memorial contributions may be made to Gonzanga College High School, 18 Eye St. N.W., Washington, D.C. 20001.