After the explosion, Will didn't expect to wake up again, especially in the past. Alive is good. Except he finds himself at the Alamo in 1836 in the body of another man doomed to die. If history repeats itself, Santa Anna is coming soon and the Alamo will fall, along with himself and 189 others.
Harry Turtledove's Guns of the South
Eric Flint's 1632
William Forstchen's Lost Regiment Series