This paper aims to recover the history of the Congress of Latin American Women held in Santiago de Chile in November 1959, using it as a snapshot to illuminate the various political currents within the Cuban delegation. At a time of rapid polarization and shifting alliances, the ideal of transnational, Latin American solidarity appealed to women activists from both Cuba’s “Old,” Marxist Left and the “New,” insurgent Left, despite their many differences. This common ground helped establish elements of cooperation between some women of the 26th of July Movement and women affiliated with the pre-revolutionary Communist Party. Although the well-known Federation of Cuban Women was established as a result of the alliances developed through participation in the Congress, these transnational, “Latin Americanist” origins of the FMC have largely been forgotten.