Final answer:
General Robert E. Lee surrendered to General Ulysses S. Grant at the McLean House in Appomattox Courthouse, Virginia on April 9, 1865, marking one of the final acts of the Civil War.
Step-by-step explanation:
The Civil War leader who surrendered to General Ulysses S. Grant at Appomattox was General Robert E. Lee. On April 9, 1865, after exchanging a series of letters with Grant, Lee met with him at the McLean House in Appomattox Courthouse, Virginia, and surrendered his Army of Northern Virginia. This event was one of the final acts of the Civil War and led to a cascade of surrenders by other Confederate generals, culminating in the war's end.
In Lee's farewell address to his troops, he highlighted that their defeat was due to the "overwhelming numbers and resources" of the Union forces rather than any lack of valor or internal problems within the Confederate army. This surrender did not immediately end the war, as there were still other Confederate armies active until later surrenders occurred, including that of Joseph E. Johnston's army on April 26, 1865 and eventually General Stand Watie in June of the same year.