The commander of the Union Army at the end of the Civil War was Ulysses S. Grant.

Appointed as General-in-Chief in March 1864, Grant played a crucial role in leading Union forces to victory. His strategies, including the implementation of total war, helped wear down Confederate resources and morale. Grant's leadership during key battles, such as Vicksburg and the Wilderness Campaign, showcased his military acumen. His ultimate triumph came with the surrender of Confederate General Robert E. Lee at Appomattox Court House on April 9, 1865, effectively bringing the war to a close.