The union general who assumed command of the army during the last year of the war was shermangrantmcclellan.

Grant

Ulysses S. Grant was the 18th President of the United States from 1869 to 1877. He was also the commanding officer of the Army.

When the Civil War started in 1861, Grant joined the Union Army. A capable man, he rose through the ranks rapidly. As a general, Grant was persistent, and he was able to gain control of the Mississippi River and to win major battles against the Confederation. In March 1864, he was promoted to Lieutenant General. His army fought the Army of Northern Virginia led by Robert E. Lee for over a year in the Overland Campaign and at Petersburg. Finally, Lee surrendered on April 9, 1865 at Appomattox, ending the war.

the answer i chose to believe is 'harmony'