Who commanded the Army of the Cumberland at the Battle of Chickamauga, which ended on September 20, 1863, in a decisive defeat for the Union side?

Who commanded the Army of the Cumberland at the Battle of Chickamauga, which ended on September 20, 1863, in a decisive defeat for the Union side?

Ulysses Grant
George Meade
Winfield Scott
William Rosecrans
George McClellan

Correct Answer: William Rosecrans