R.P. Hunnicutt is known by those interested in tanks and armor as the author of a ten volume set detailing the history and development of US armored vehicles. His books are essential to anyone doing serious research into US AFV history. (Note: he links below are to recent Echo Point reprints of his books, with the exception of Firepower.)
Sherman: A History of the American Medium Tank
Patton: A History of the American Main Battle Tank
Stuart (History of the American Light Tank, Vol. 1)
Firepower: A History of the American Heavy Tank
Abrams: A History of the American Main Battle Tank, Vol. 2
Sheridan: A History of the American Light Tank, Volume 2
Bradley: A History of American Fighting and Suport Vehicles
Half-Track: A History of American Semi-Tracked Vehicles
Armored Car: A History of American Wheeled Combat Vehicles