From
www.culturaltourismdc.org:
The powerful bronze statue dominating Sheridan Circle depicts a dashing Philip H. Sheridan, Civil War cavalry commander of the Army of the Shenandoah for the Union. He sits astride Rienzi, his partner through 85 battles. Gutzon Borglum, sculptor of Mount Rushmore, created the statue in which Sheridan waves his hat to rally his retreating men at an important battle near Winchester, Virginia. After this Union victory, Rienzi was renamed Winchester. The grand houses surrounding the circle reflect the westward movement of the elite in the early 20th century.