The Michigan Jacobsens a Military Heritage Now IN Indiana

My Father was a career Military Man and made (E-7) and I was in and made master Sargent (E-8) in before I finished, and now my son is in the National Guard as a Sargent (E-5)and is planning on making it a career and I suppose that counts for us as a Grandfather, Father and Son being a military Family heritage, that I know about.

What I don't know about (Yet) is my great Grandfather, and the Jacobsens' that have been here from the founding of this great nation.
My only memory of my Grandfather "Peter Jacobsen of Detroit area of Michigan" was from a very young age of three years; when I first remember my father (Harry R. Jacobsen) talking about him; he was tall, slender with very white hair (according to pictures I have) and I never met him.
I would like to recreate our family tree from the earliest possible time and help to establish our Military History for the Jacobsen Line having served this county.