The San Marcos Stakes – formerly the San Marcos Handicap – has been run since 1952. In that first running, at a mile on the main track, the 1950 Horse of the Year, Hill Prince, made his first start as a 5-year-old and won under a pull, setting himself up as the favorite for the Santa Anita Handicap three weeks later.
Unfortunately, Hill Prince was beginning to show the wear and tear of his 29-race career. He finished fifth in the Handicap, under 129 pounds, and was retired to stud before he had a chance to cool out.