Mollie McCarty was by bred by Adolph Mallard and was by Monday (by Colton, by Lexington), who had broken down early in his career, but when standing in Marin County, California, he sired Mollie McCarty as well as Joe Hooker, sire of the good filly, Yo Tambien (bred by Winters).

At the end of her second season she won a $10,000 purse in a four-heat race in San Francisco, California for females of all ages.

There was a clause in that race which effectively said that if a horse was distanced (meaning they'd given up or were so far behind they might as well give up), no prize would be awarded.

When Mollie McCarty was undefeated after thirteen races, Winters sold her to Lucky Baldwin.

Due to public demand that the best in the west should race the best in the east (at least 30,000 people showed up on the day: July 4, 1878), Bud Doble, training for Baldwin, sent her out against Ten Broeck.

Like Mollie in the west, Ten Broeck, owned and bred by John Harper, had run out of competition in the east.

A book written by Colonel John F. Wall called Famous Running Horses records that Ten Broeck was laboring badly, did not sweat, was glassy eyed, and had to be whipped through the match.

In her last season, she won the Garden City Cup in Chicago, Illinois and a purse race in San Francisco.