Wheeler had been a general in the Confederate Army in the Civil War. By the Spanish American War, he was 62 years old and while the fighting spirit was undiminished, his attention to details left something to be desired. From Wikipedia.
Approaching Las Guasimas de Sevilla on June 24, American reports suggested the Spaniards were digging in with a field gun; however, Cuban scouts contradicted these, revealing the Spaniards were preparing to abandon their position. In fact, the Spanish troops at the position had received orders to fall back on Santiago. Wheeler requested the assistance of the attached Cuban forces in an immediate attack, but their commander, Col. Gonzales Clavel, refused. Wheeler decided to attack anyway, rushing his men forward with two guns to the front, with Colonel Young's brigade leading the advance against the Spanish columns in what came to be called the Battle of Las Guasimas, the first major engagement of the war.
During the excitement of the battle, Wheeler supposedly called out "Let's go, boys! We've got the damn Yankees on the run again!" Wheeler's forces moved to encircle the Spaniards' first battle line, assaulting its front and right flank, but were repulsed. During a pause in the fighting, both sides reinforced their positions. The Spaniards sent forward 2 companies of the San Fernando Battalion, along with the artillery. After midday the U.S. attack was renewed, but Spanish Comandante Andrés Alcañiz, leading the Provisional de Puerto Rico Battalion, once again checked the American assault.