When the world’s best golfers play Congressional this week in Bethesda, Md., little evidence of the mayhem that preceded them by more than 65 years will remain. After the war, the federal government restored the course to its original splendor. Golf shots replaced gunshots.

“But Congressional remains a pivotal place in the history of the country,” Charles Pinck, president of the O.S.S. Society, said. “It’s the birthplace of the American Special Forces. A group like the Navy Seals — the Congressional Country Club is where it all started.”

It was an eclectic collection of fighting men who arrived at Congressional in 1943. Most were drawn from the United States military, pulled aside because of one aptitude or another, like familiarity with a foreign language. They would be asked if they wanted to volunteer for hazardous duty and would face physical and psychological testing to determine if they could handle life behind enemy lines. Founded by the World War I hero William Donovan, who was known as Wild Bill, the O.S.S. recruited from civilian trades and sought well-traveled intellectuals as well. An ideal O.S.S. candidate was once described as a “Ph.D. who can win a bar fight.”

The troops at Congressional, known to them as Area F, were generally trained in groups of about 200 men. From 1943 to 1945, more than 2,500 soldiers passed through Congressional. The officers lived in the clubhouse, where the grand ballroom was turned into a classroom and the dining room was a mess hall. They did little marching or traditional, regimented military drilling.

“The idea was not to build discipline but innovation,” said John Whiteclay Chambers II, a history professor at Rutgers University who has written extensively about the O.S.S. training. “They wanted to create men who would be daring, aggressive and imaginative. They had them work together to build a stone bridge over a creek on the golf course. Then they would ask them what’s the best way to demolish it with plastic explosives.”

Nighttime brought the grounds alive with missions not unlike the child’s game capture the flag, except the sentries were armed and the commandos carried scalpel-sharp stilettos. Pity the poor milkman assigned to make deliveries to Congressional; he was the target of more than one ambush.