He attended the United States Military Academy in West Point, New York, and was captain of the Cadet golf team.

In 1974, Yancey's illness resurfaced and led him to be involved in a series of bizarre incidents, for which he was at various times arrested, incarcerated, and institutionalized.

Yancey credited Dr. Jane Parker of Payne Whitney Hospital for correctly diagnosing his condition and prescribing lithium.

He also put on seminars, golfing clinics, tournaments and other charitable events to raise money to treat illness and educate the public.

[3] Yancey suffered a fatal heart attack in 1994 at age 56 at the Franklin Quest Championship in Park City, Utah.

While on the practice tee preparing for the first round, he experienced discomfort and made a second visit to the first aid tent; he went into cardiac arrest and was pronounced dead at a local hospital a short time later.