[4] Parsons and his brother were among the eleven men who attended the infamous meeting held at the Gimnasio Solé on 29 November 1899 which saw the birth of Foot-Ball Club Barcelona.

[1][3][4][14] Together with Bartomeu Terradas, Arthur Witty and team captain Joan Gamper, he was part of the Barça side that participated in the first regulated football championship played on the Iberian Peninsula, the Copa Macaya in 1900–01, in which he scored 8 goals, including two hat-tricks in 0–13 and 14–0 trashings of Franco-Española, but despite his goalscoring prowess, Barça finished the tournament as runner-ups to Hispania AC.

In the following season, however, he helped Barcelona win the 1901–02 Copa Macaya, the club's first-ever piece of silverware, netting two goals on the final matchday on 23 March 1902 in a 15–0 victory over Català FC.

In 1902, Parsons was a member of the Barcelona team that participated in the Copa de la Coronación (predecessor of Copa del Rey), featuring in the semi-finals against Real Madrid (then Madrid FC),[17] the very first El Clásico in history, and in the final, where he scored Barça's only goal in a 1–2 loss to Club Vizcaya.

[3] In 1912, Parsons, together with Joan Gamper, Udo Steinberg and Arthur Witty, joined the Comité Athlétic of FC Barcelona as a referee and under the presidency of Joaquín Peris de Vargas.