He rode for seven years as a gentleman amateur jockey in England and France before turning professional in 1903.
[3] In 1905, within 18 months of turning professional as a jockey, Hartigan began his career as a racehorse trainer, succeeding his uncle Willie Moore at his stables in Weyhill, Hampshire.
In 1915 he won with Vaucluse, owned by the 5th Earl of Roseberry and ridden by Fred Rickaby Jr.[4] Hartigan was again successful in 1919, winning with Roseway, owned by Sir Edward Hulton and ridden by Albert Whalley.
[5] Hartigan's most famous success over fences came at the 1930 Grand National at Aintree, when Shaun Goilin, owned by Walter Midwood and ridden by Tommy Cullinan, won the race.
[7] A special feature on Hartigan in the 9 February 1936 edition of the Weekly Dispatch described him as "the most hard-working and conscientious of racehorse trainers".