General Valeriano Weyler y Nicolau understood very quickly that the key to a Spanish victory over the insurgents was to strip the guerrillas of their abilities to live off the land and camouflage themselves in groups of civilians. To this end, he began a policy of moving Cuban civilians to central locations where they would be under the control of the Spanish army. In addition, he put the entire island under martial law.
The policy had disastrous consequences. Unlike many concentration camps in the twentieth century, the idea was to keep the Cuban civilians alive and protected until the Spanish were victorious. Unfortunately, at least 30% perished from lack of proper food, sanitary conditions, and medicines. The policy generated severe anti-Spanish feeling in the United States which helped propel it into war in 1898. Finally, it did not benefit the Spanish in the war.