Complex sentence: Upon learning of Bolívar's dream of liberating and creating a unified Latin America, which included Puerto Rico and Cuba, Valero de Bernabé decided to join him and stopped in St. Thomas where he established contacts with the Puerto Rican independence movement.
Split into simpler sentences: Upon learning of Bolívar's dream, Valero de Bernabé decided to join him. He went to St. Thomas, where he established contacts with the Puerto Rican independence movement.