Reddit mentions of Bruce Catton's Civil War (Mr. Lincoln's Army/Glory Road/A Stillness at Appomattox)

There is really only one answer to this question, and that is Bruce Catton's Civil War trilogy.

Bruce Catton's works introduced me to the ACW. His writing isn't always very thorough from an academic perspective (fewer citations, etc) but his florid prose is a great way to get hooked into the broader Homeric narrative of the conflict and how it plays on the American consciousness. He wrote a few general histories, including the classic 1960 American Heritage Picture History of the Civil War (if you want to go the pictorial route). But the best thing of his, to my recollection, is the beautifully-written Army of the Potomac trilogy (Mr. Lincoln's Army, Glory Road, and A Stillness at Appomattox), which you can now get in a single volume (https://www.amazon.com/Bruce-Cattons-Lincolns-Stillness-Appomattox/dp/0517447711). Its focus, however, is on the Union's Army of the Potomac, so you only see the war through one side and theater (the Eastern campaigns).