Having risen to the rank of colonel of artillery in the Federal Army of the Porfiriato, Ángeles was promoted to general during the brief presidency of Francisco I. Madero.

He went on to study in the Instituto Literario in Pachuca, subsequently entering the Military Academy in Mexico City in 1883 at the age of 14.

[3][4] Concentrating on raising the professional level of the officers of the Federal Army through improved education, he took on various lectureships in the military academy.

As (Mexico's) Inspector General of Munitions at the Sharpshooting Academy at Mailly, Ángeles perfected the "French 75," which would become one of the more effective weapons in the Great War.

While he was director, he had much contact with President Madero, and developed a reputation as a cultured dignified officer and a man of honor.

Ángeles, with Madero's concurrence, changed the harsh military tactics and offered amnesty to those revolutionaries who agreed to lay down their arms.

Ángeles unleashed aerial bombardment and modern counter-insurgency warfare against those who refused to surrender, but he did not deliberately target civilians.

[10][11][12][13] In February 1913, a reactionary coup d'état known as La decena trágica ended the Madero government when a conservative military faction attacked the National Palace.

President Madero appointed General Victoriano Huerta to lead the loyal troops, and then traveled to Morelos to confer with Ángeles.

Huerta, supported by the conservative rebel units, arrested President Madero, Vice-president Pino Suarez, and General Ángeles.

However, the powerful Sonoran faction considered Ángeles to be a holdover of the old Díaz regime, and treated him with suspicion and hostility.

[34][35] While in Texas, he joined the Liberal Mexican Alliance, which sought to bring together exiles of various ideological persuasions linked by the common aim to stop the war and form a coalition government.

Ángeles, a conciliator, pacifist, and philanthropic socialist wanted peace, but he was unable to convince Villa to cease hostilities.

Knowing that Carranza would never pardon him, Ángeles made a heroic and impassioned defense in response to his enemies' case for the prosecution.