Affectionately was the daughter of 1956 American Horse of the Year Swaps, out of the exceptional racing mare Searching. Searching's dam was Big Hurry, by Black Toney and out of the best "Blue Hen" mare of them all, La Troienne. Searching's sire was War Admiral, winner of the American Triple Crown of Thoroughbred Racing, whose own sire was Man o' War, arguably the greatest American race horse of the twentieth century.
In the Blood-Horse magazine List of the Top 100 U.S. Racehorses of the 20th Century, with Affectionately's great grand damsire at no. 1, her dam sire at no. 13, her sire at no. 20, and Affectionately herself at no. 81, Affectionately's heritage consists of a tradition of Thoroughbred breeding and racing at its best.
Foaled on April 26, 1960 at the farm of Dr. Charles Hagyard near Lexington, Kentucky, she was bred by the partnership of owner/trainer Hirsch Jacobs and Isidor Bieber. Jacobs, who was a Hall of Fame conditioner, said of her: "She's the best horse I've ever trained." Jacobs had trained Stymie and Hail to Reason. Campaigned under the name of Jacob's wife, Ethel Jacobs, Affectionately won nine of her first ten starts. In the Matron Stakes she was finally beaten by Smart Deb, herself a fine filly. When Affectionately won as champion two-year-old filly in 1962, she shared the honor with Smart Deb.
At ages three and four, Affectionately was very good, winning two Interborough Handicaps, the Vosburgh, and the Correction Handicap. But when she turned five, she gained the successes that put her on the list of the 100 best racehorses of the twentieth century. Under high weights, she took the Top Flight Handicap and the Vagrancy Handicap, as well as a number of other important stakes races. She retired sound, with eighteen stakes wins, as one of only two females to break the half-million-dollar earnings mark. As a broodmare, she was just as brilliant as she was a racehorse. Her first foal was 1970 American Horse of the Year Personality (sharing this honor with Fort Marcy).
Affectionately died in 1979. Ten years later, she was voted into the Hall of Fame, an honor her dam Searching was accorded only the year before.