Bailey Cove Sci-Fi: Princess of Mars

John Carter, a gentleman from Virginia and a Civil War veteran, unexpectedly finds himself on to the red planet, scene of continuing combat among rival tribes. Captured by a band of six-limbed, green-skinned savage giants called Tharks, Carter soon is accorded all the honor of a chieftain after it's discovered that his muscles, accustomed to Earth's greater gravity, now give him a decided advantage in strength. (#1 in the The Martian Series)