 After concluding his studies, he returned to Argentina and joined the nascent independence movement, which he helped to organize.Along with Domingo French, he led a group of revolutionaries known as "the Chisperos", who played a pivotal role in the "Semana de Mayo", the week beginning on May 18, 1810, which culminated in the May Revolution.Along with French, he distributed white and blue ribbons to the populace, so that patriots could distinguish themselves from royalists.