Joshua Chamberlain
Chamberlain was a college professor at Bowdoin College before the U.S. Civil War. When the faculty refused him permission for a leave of absense so that he could enlist he took a sabbatical and enlisted anyway.
He played a Key role in the Battle of Gettysburg as depicted in Michael Shaara's Pulitzer Prize-winning historical novel about Gettysburg, The Killer Angels, and the movie based on that novel, Gettysburg (in which Chamberlain was played by actor Jeff Daniels, who repeated that role in the Gods and Generals prequel).
Chamberlain was later seriously wounded in the war and was propted to General but survived and went on to become governor of Maine and President of Bowdoin College where he was proud to say that he eventually taught every course in their curriculum with the exception of mathematics
“In great deeds, something abides. On great fields something stays. Forms change and pass; bodies disappear, but spirits linger, to consecrate the ground for the vision-place of souls. And reverent men and women from afar, and generations that know us not and that we know not of, heart-drawn to see where and by whom great things were suffered and done for them....”