From his enlistment in 1861 to mustering out at the end of the American Civil War, Martin Haynes kept up a voluminous correspondence with the girl he'd left behind him: Cornelia Lane. Throughout the bloody fighting at Gettysburg, Malvern Hill, and other famous battles, it is remarkable how little it seems Haynes withheld from the woman who became his wife.A very popular song title during the Civil War, every soldier knew "The Girl I Left Behind Me"...