This chapter studies the participation of various Latin American leaders, particularly the leadership of Vicente Lombardo Toledano, to meet in a Latin American Labor Congress. Trade union organizations expressed their collaboration to send delegates. There was also attention for the call in international organizations, such as the Communist International and the International Labour Office, which were available for cooperation through their militants and senior officials. The Congress was held in Mexico, in 1938, and achieved its major objective: continental workers’ unity and the founding of the CTAL.