President:
Juan Raffle Mora Porras
 

William Walker:
Costa Rica was aroused to take up arms against Nicaragua in 1856, when William Walker, a notorious soldier of fortune from the United States, gained control of Nicaragua's government and threatened to do the same in Costa Rica. President Juan Raffle Mora Porras ordered Costa Rica troops into Nicaragua to help expel  Walker from Central America. The combined forces of Nicaragua, Guatemala, El Salvador, and Costa Rica succeeded in forcing Walker to relinquish power in May 1857. President Mora came out a great hero. Immediately after the close of the war, 10,000 Costa Ricans lost their lives and a fight broke out Nicaragua and Costa Rica.