American Civil War and Revolutionary War
Here are some pretty solid history books. I'm leaving out the WW1, WW2, European and Asian that I like but I'm including a couple of other American History Books.
Revolutionary War
Washington's Spies by Alexander Rose
Benedict's Navy by James L. Nelson
1776 by David McCullough (fictional but extensively researched to the point it basically is nonfiction)
His Excellency by Joseph J. Ellis
Glorious Cause by Robert Middlekauff
The Swamp Fox: How Francis Marion Saved the American Revolution by John Oller
Valley Forge by Bob Drury
Forced Founders by Woody Holton
West of the Revolution by Claudio Saunt
When the United States Spoke French Five Refugees Who Shaped America by Francois Furstenberg
Civil War
Civil War on the Western Border by Jay Monaghan
Discovering the Civil War in Florida by Paul Taylor
Storm Over the Land by Carl Sandburg
A Vast and Fiendish Plot by Clint Johnson
What They Didnt Teach You About the Civil War by Mike Wright
Florida During the Civil War by John E. John's (much more detailed than the first)
Mosby's Rangers by Jeffry Wert
Confederate Florida The Road to Olustee by William Nulty (by far the most detailed and descriptive about the biggest battle in Florida but barely covers anything else)
The Civil War in the Western Territories by Ray Colton (unlike Monaghan which covers Bloody Kansas and Missouri this covers when Texans tried to seize Arizona, New Mexico and Colorado and their major loss at Glorietta Pass as well as Mormon battles in Utah and various Indian Tribe campaigns as well as the few skirmishes in California)
Rebel Private Front and Rear by William A Fletcher (excellent personal memoirs of a frontline soldier who fought during the Seven Days, Gettysburg, Chickmauga, Manassas, Fredericksburg and more)
Incidents in the Life of a Slave Girl by Harriet A Jacobs
Other Early US History
Jefferson's War: America's First War on Terror 1801-1805 by Joseph Wheeden
1491 and 1493 by Charles Mann (two separate books)
Christopher Columbus and the Conquest of Paradise by Kirkpatrick Sale
History of the Second Seminole War by John Mahon
Empire of the Summer Moon by S.C. Gwynne
The Other War of 1812: The Patriot War and the American Invasion of Spanish East Florida by Jamee Cusick
The Blood of Heroes by James Donovan