The Puerto Rican delegation was freely elected by those eligible to vote (male Caucasian property owners), in a rare exercise of political openness in the colony. Segundo Ruiz Belvis was elected to the Junta representing Mayagüez, something that horrified the then governor general of the island. To the frustration of the Puerto Rican delegates, including its leader, José Julián Acosta, the Junta had a majority of Spanish-born delegates, which would vote down almost every measure they suggested. However, Acosta could convince the Junta that abolition could be achieved in Puerto Rico without disrupting the local economy (including its Cuban members, who frowned upon implementing it in Cuba because of its much higher numbers of slave labor). Once he became prime minister in 1870, Castelar did approve an abolition bill, praising the efforts of the Puerto Rico members, sincerely moved by Acosta's arguments.