His father, Joaquim, was the manager of the Companhia de Navegação Fluvial and, according to the biographer of Tasso Fragoso, to whom “the province [of Maranhão] already owed the foundation of several industrial companies”.

In October, when relations between the emperor, Dom Pedro II, and the army were tense, he spoke on behalf of his colleagues in honor of Benjamin Constant, affirming everyone's determination to accompany the professor “in the transformation about to take place in our country”.

Around November 15, upon hearing of movements for the proclamation of the Republic, Tasso Fragoso, in uniform and armed, joined other comrades and headed for the school, where everyone awaited the arrival of Benjamim Constant and General Manuel Deodoro da Fonseca.

Subsequently, he took over, together with the then officer cadet Cândido Mariano Rondon, to ascertain the position of then Admiral Eduardo Wandenkolk regarding the movement, which ended up toppling the monarchy and implemented the new form of government in the country.

In 1891, he assumed the Head of the Department of Works and General Transportation of the Federal District - then Rio de Janeiro -, holding the position until the month of April of the following year.

Appointed military attaché to the Brazilian legation in Argentina, Tasso Fragoso traveled to that country in July 1909, being promoted to lieutenant colonel in December of that same year.

During this period, he played an important role in implementing compulsory military service and in remodeling the Army amid the changes taking place as Brazil entered in World War I. Tasso Fragoso attained generalship in 1918.

Then, together with General Mena Barreto and Rear Admiral Isaías de Noronha, he headed and led the Junta Governativa that replaced the deposed President and transferred power to Getúlio Vargas, commander of the revolutionary forces.

Tasso Fragoso refused the suggestion, claiming it would not be honest, after benefiting for years from his father's appeal, coming out to denounce him and annul him for personal gain.