On July 1st, 1898 soldiers from the 10th Cavalry and the First U.S. Voluntary Cavalry (AKA: "Rough Riders) under the leadership of this man charged up Kettle Hill under heavy fire. The units storming Kettle Hill raised a cheer from the American Forces still pinned under fire below San Juan Heights. That and the help of the newly positioned Gatling guns to within six hundred yards of the Spanish lines was enough to spark the famous "Charge up San Juan Hill". At the Same time, the Rough Riders, poured machine gun fire into the Spanish Flank and charged down Kettle Hill directly into the Spanish positions. Spanish resistance disintegrated and the Americans found themselves overlooking Santiago, and the next day they began a siege of the city. Name the leader of the Rough Riders who took Kettle Hill.