Alfred Gwynne Vanderbilt, the elegant symbol of the sportsman in high society when he was the impresario of horse racing and the pillar of one of the most aristocratic families in America, died on Friday at his home in Mill Neck, N.Y. He was 87.

He was born in London and educated at St. Paul’s School and Yale.

His grandfather, Cornelius Vanderbilt II, was reputed to be the world’s richest man. His mother, Margaret Emerson, came from Bromo-Seltzer wealth.

His father, Alfred Gwynne Vanderbilt, died after giving his life jacket to a woman on the Lusitania when the ship was sunk by a German submarine in the Atlantic in 1915.

Surrounded by family history, wealth and opportunity, Mr. Vanderbilt took a direct route to the racetrack and spent his life breeding, owning and racing his horses.

Even at 80, tall and richly groomed, he remained the very model of the racing blueblood. He ran Pimlico and Belmont Park while in his 20s; he pioneered the use of the starting gate and the photo finish; he skippered a PT boat in the Navy; and he shot lions with Ernest Hemingway in Africa.

Four times he was voted by New York’s turf writers as “the man who did the most for racing.”

But his shining moments came through the brilliance of one gray colt, Native Dancer, who won 21 of his 22 races and lost the other one, the 1953 Kentucky Derby, by the length of his head.

“Since the first time I went to the races at Pimlico at the age of 9,” Mr. Vanderbilt once said, “I have had this wonderful feeling about racing. I don’t go to the races because I just love horses. It’s like the person who goes to the circus and falls in love with the whole show, not just the elephants.”

He stayed in love with the whole show for the rest of his life, amusing people by inventing witty and salty names for his horses and appearing constantly on the backstretch at the Belmont and Aqueduct racetracks.

Rain or shine, winter or summer, he was there, a well-dressed and graceful man in his 80s with failing eyesight and an informal manner.

He would walk through the staff offices for morning conversations and eventually wind up in his box for several races before being driven home again to Mill Neck on the North Shore of Long Island.

“My father went to the racetrack today,” his son Alfred said on Friday.

“He came back and was changing clothes when his secretary said he keeled over.”