Cornelius C. Jadwin, 85, a retired Army colonel and former general manager of Rosecroft Raceway in Oxon Hill, died of emphysema March 3 at Fauquier Hospital in Warrenton.

Col. Jadwin, who lived in Warrenton, was born in North Carolina. He graduated from old Central High School in Washington and the U.S. Military Academy at West Point in 1918.

A cavalryman, he was a member of the U.S. equestrian team at the 1936 Olympics in Berlin.

Early in World War II, he spent a year as an assistant military attache in Rome and later was an attache in Bulgaria and Turkey. In 1943, he became an intelligence officer at the Pentagon. He retired from active duty in 1948 as chief of staff of the Military District of Washington.

Col. Jadwin worked for Allied Van Lines here before becoming general manager of Rosecroft in 1950. He retired a second time in 1953.

He had been commodore of the Corinthian Yacht Club and was a member of the Army & Navy Club. He had been a vestryman of St. James Episcopal Church in Warrenton.

His marriage to the former Eleanor Topliff ended in divorce.

Survivors include his wife, the former Margaret Keith Hamilton, of Warrenton; a son by his first marriage, Edgar, of Madison, N.J.; two stepsons, James C. Hamilton of Richmond and Barry Hamilton of Greenville, Miss.; a stepdaughter, Margaret Stephens of Fort Lauderdale, Fla.; and two grandchildren