Final answer:
General Weyler's policy of reconcentration during the Spanish-American War intensified American sympathy for the Cuban rebels due to the crowded and unsanitary conditions in the camps.
Step-by-step explanation:
General Weyler, known as "The Butcher," had a significant impact on Americans during the Spanish-American War. His policy of reconcentration, which involved relocating the Cuban population to fortified camps, resulted in crowded and unsanitary conditions, leading to the death of approximately one in every four Cubans inside the camps. These harsh tactics by Weyler heightened American sympathy for the Cuban rebels and led to increased outrage in the American public.