Mansfield was recognized as having significant potential as a stallion with his first successes as Reserve Champion weanling at the 1920 Vermont State Fair and Champion Weanling at the Woodstock, Vermont Fair. In 1928, 1929 and 1931, he was grand champion at the Topsfield, Massachusetts Fair.
He was purchased for and donated to the USGMHF by C.C. Stillman, first Secretary, Morgan Horse Club, in 1922 and was used as a stud alongside of his sire Bennington. Mansfield was the lead sire at the farm in the 1930s.
Mansfield, the first of the golden crosses (Bennington x Artemesia), was purchased as a two year old by C. C. Stillman. In the same year the farm also acquired his dam Artemisia, who would produce ten living foals, including Ulysses, Canfield, Querido.
Became lead sire at the USGMH Weybridge, VT.