Question

How was the Chancellorsville victory turned into defeat?

The Confederates won the battle but had to retreat.
The Union army held the town.
The Confederacy lost a key leader.
The Union won but lost key weaponry.

Answer 1

Battle Of Chancellorsville Summary:  The Battle of Chancellorsville, April 30–May 6, 1863, resulted in a Confederate victory that stopped an attempted flanking movement by Maj. Gen. Joseph "Fighting Joe" Army of the Potomac against the left of Gen. Robert E. Lee’s Army of Northern Virginia. The Southern victory was diminished by the loss of Lt. Gen. Thomas "Stonewall" Jackson, mortally wounded by his own men who mistook him and his staff for Union cavalry, a loss that would have far-reaching effects on the Civil War.

Answer 2

So C.

The Confederacy lost a key leader.