The Sleeping Soldier by Aster Glenn Gray (epub)
After a century-long sleep, a Union soldier wakes up in 1965.
Cavalry lieutenant Russell Krause is all at sea in this strange new century of electric lights and automobiles. But he soon acquires a guide: Caleb O’Connor, a kind-hearted, history-loving college student with secrets he’s desperate to hide. Caleb is gay, and he’s completely smitten with this lively, warm-hearted soldier, who has swiftly become his best friend.
But Russell’s nineteenth century understanding of friendship is far more affectionate than any 1960s friendship is allowed to be. In between telling Russell about escalators, record players, and the Civil Rights movement, Caleb has to explain that men in 1965 are no longer allowed to hold hands or share beds or kiss… which is tough, because Caleb would love to be kissing Russell.