As the fifth president in five turbulent years, Sam was forced to contend with a revolt against his own regime, led by Dr. Rosalvo Bobo, who opposed the government's expanded commercial and strategic ties with the United States. Fearing that he would share the same fate as his predecessors, Sam acted harshly against his political opponents, particularly the better educated and wealthier mulatto population. The culmination of his repressive measures came on 27 July 1915, when he ordered the execution of 167 political prisoners, including former president Zamor, who was being held in a Port-au-Prince jail. This infuriated the population, which rose up against Sam's government as soon as news of the executions reached them.