The removal of the Lee statue has been highly controversial, but Mayor Mitch Landreiu called the removal of the statue part of the "healing" of New Orleans. He said that the Confederacy was "on the wrong side of humanity."
Lee, whose surrender to Union General Ulysses S. Grant in 1865 effectively ended the Civil War, had complicated and historically disputed views on slavery. During the war, he held that he was fighting for his native Virginia, and not for the causes of slavery or secession, which he disagreed with. The Confederacy for which he fought was, of course, was officially fully on board with both notions.
