Lost Civil War Relative

I have a Great Great Great and a few more Greats Grandfather who served and died during the American Civil War. He served for the state of Michigan and died as a POW. He is now buried in Pennsylvania. I am attempting to find out more on him but my Googling is not working out. All I know is his last name, Lundy, and he was from Marcellus, MI Michigan. Does anyone know how I can find out more about this long lost relative?