Here are some I like.
1) Albion's Seed, Four British Folkways in America by David Hacket Fischer
This one is monumental, explains who we are and who they are.
2) Born Fighting, How the Scots-Irish Shaped America by James Webb
The Scots-Irish (Border People) are one of the four British folkways Fischer writes about. Mr Webb is a fine man and has written a fascinating book.
3) Bound Away, Virginia and the Westward Movement by David Hackett Fischer
Another good one by Fischer, he's a scholar.
4) Flowering of the Cumberland by Harriette Simpson Arnow
She wrties about the early Southerners of the late 18th and early 19th centuries in the Cumberland valley. Lot's of interesting facts.
5) Thomas Jefferson, A Life by Williard Sterne Randall
One volume biography
6) Undaunted Courage by Stephen E Ambrose
Story of the Lewis and Clark Expedition, Lewis from the planter class and Clark of the Border people (Scots-Irish).
7) Appalachia, A History by John Alexander Williams
Interesting read.
8) How the Scots Invented the Modern World by Arthur Herman
So few people did so much, greatly influenced America. Were they American before there were Americans?
9) The Civil War, A Narrative (3 Volumes) by Shelby Foote
Over 3000 pages of readable history. It reads like a novel, he was a great storyteller. After reading the first 50 pages knew I'd read it all
10) Stonewall Jackson, The Man, The Soldier, The Legend by James Robertson
Loved this one, gets into what made the man tick. His men loved him. One time while leading a long column of his men, he needed to go to the rear, but went the long way to avoid being cheered by his men. It embarrassed him, they loved him all the more. The modern world doesn't understand a man like this.
11) Nathan Bedford Forrest by Jack Hurst
Good one about this military genius.
12) What If?, Volume 3 edited by Robert Cowle
Must admit I like alternative history, three essays here about the war.
a) If the Lost Order Hadn't Been Lost. Lee Humbles the Union, 1862
by James M Mcpherson
b) The Nortwest Conspiracy
by Thomas Fleming
c) Beyond the Wildest Dreams of John Wilkes Booth
by Jay Winik
13) Sgt. York, His Life, Legend and Legacy by John Perry
Admire this man. He was the hero of WWI, who was given a parade in New York City. He was offered a lot of money to make endorsements (in todays money he would have been a millionaire) but refused saying, "Uncle Sam's uniform is not for sale". The modern world doesn't understand this man either. A poor man from Tennessee went home. His Congressman Cordell Hull who had been sent to NYC to take care of him stated that after I heard him say what he said, I knew he didn't need me.
14) The Southern Nation, The New Rise of the Old South by R Gordon Thorton