Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. Ranald Slidell Mackenzie (July 27, 1840 January 19, 1889) was a career United States Army officer and general in the Union Army during the American Civil War, described by General Ulysses S. Grant as its most promising young officer. He also served with great distinction in the following Indian Wars. Mackenzie was born in Westchester County, New York, the nephew of Confederate States of America diplomat John Slidell and the brother of Lt. Commander Alexander Slidell MacKenzie, United States Navy. He initially attended Williams College where he was a member of The Kappa Alpha Society and then accepted a nomination to the United States Military Academy where he graduated at the head of his class in 1862 and immediately joined the Union forces already fighting in the Civil War.