[3] Labeled a terrorist organization by the Mexican authorities, the LC23S engaged in numerous violent attacks, both against what they considered their "class enemy" (the bourgeoisie) and the authoritarian government of the Institutional Revolutionary Party (PRI).

[4] Without having a social base in the workers' sphere and with a disbandment of militants who saw an opportunity of activism in the aftermath of the new legal framework, the September 23rd Communist League disappeared at the beginning of the eighties.

The march started at the Casco de Santo Tomás, and proceeded through Carpio and Maestros Avenues so the protesters could take the Mexico-Tacuba Causeway, and eventually end up at Zócalo.

Even though, in Mexico City, the social unrest and the following repression that started back in the fifties and sixties greatly influenced the development of subsequent popular movements, in the rest of the country this was not the case.

This is the main reason why two of the most important guerrilla organizations of the late sixties appeared in the hills and jungle of Guerrero: the Partido de los Pobres (Party of the Poor, PdlP) and the Asociación Civíca Nacional Revolucionaria (National Revolutionary Civic Association, ACNR).

The first person to develop the idea of the unification of the armed organizations at the national level was Raúl Ramos Zavala, who since 1969, by means of texts such as "El Proceso Revolucionario en México, el tiempo que nos toco vivir" (The Revolutionary Process in Mexico, the Time We Live),[5] criticized the Mexican Communist Party, considering that it had not been consistent with the political needs of the youth in the face of the 1968 movement, since no formal condemnation was made after the events of the bloody October 2 massacre.

After the death of Ramos Zavala, Ignacio Arturo Salas Obregón founded the Organización Partidaria (Partisan Organization) in 1972, and wrote texts known as the Madera Viejos, (which are called Madera I, II, III and III-Bis), which developed Ramos Zavala's proposals on unification in a single organization at the national level, systematizing the political approaches that should begin to govern proletarian politics in Mexico.

To this end, "Oseas" made an analysis of the conditions of the workers' struggle in Mexico, as well as the level of the existing relations of production, with the purpose of constructing a theory that would explain and sustain the actions of the organization to which they aspired.

These documents were personally delivered by him to the various leaders of existing organizations in Mexico and a first National Meeting was convened on March 15, 1973 in Guadalajara, Jalisco for discussion and analysis.

[7] From this discussion arose the “Manifiesto al Proletariado: Questiones basicas del Movimiento Revolucionario, 1973” (Manifesto to the Proletariat: Basic Issues of the Revolutionary Movement, 1973).

This first proposal is one of the mostly widely accepted and characterizes the LC23S for their proactive offensive strategy, where expropriations (bank robberies), police killings, propaganda distribution and clashes with the security services were common.

This timeline places the end of the League after the failed kidnapping attempt of the sister of the Mexican president-elect, Margarita Lopez Portillo, and the death of Oseas successor, David Jiménez Sarmiento (El Chano).

This is due to the fact that even though, by 1976, casualties were high and the persecution by the Mexican government was at its strongest point, there was never a complete crackdown of the National Directive (Coordinadora Nacional).

According to records by the Dirección Federal de Seguridad (DFS, Mexican secret police), as well as interviews with former members of the organization, by 1981 recruitment of new militants was still taking place throughout the country, especially at university campuses and rural teacher schools (Escuelas Normales).

It is the only guerrilla organization in Mexico, created in the seventies, which came to be considered as an actual internal threat to national stability, due in part to the large number of militants they had, as well as to the extent of the territory in which they had presence.

After the disappearance of their main leader following a shootout on April 25, 1974,[10] the process of polarization and division within the LC23S exacerbated, leading to accusations of infiltration, treason, revisionism, bourgeois opportunism, militarism, etc.

After the death of David Jimenez Sarmiento, the increased violence put forward by the security forces, and the changing political landscape, the LC23S went through a restructuring and self-criticism process.

While on the one hand the LC23S was suffering casualties thanks to the BE, on the other side, the Political Reform (Ley Federal de Organizaciones Políticas y Procesos Electorales, LFOPPE) of 1977 was the final blow to the organization.

Said law opened a small political space to the opposition, as well as permitted once again the legal participation of the Mexican Communist Party in national and local elections.

On September 23, 2019, speaking on behalf of the Presidency of Andrés Manuel López Obrador, Interior Secretary Olga Sánchez Cordero apologized to Martha Camacho Loaiza, the wife of a leader of the Liga Comunista 23 de septiembre, who was tortured in 1977.