A significant number of family members served in the armed forces. During World War I, my father's uncle was gassed in France, and another uncle served in the cavalry on the Mexican border.
My mother had an uncle who was a "mule skinner." He led the pack trains of mules to the front lines. He had mules shot out under him by German snipers.
In World War II, my father served in the Pacific and his sister served as an Army nurse. My mother had three brothers who served -- two in the Army, one in the Marines. The brother in the Marines was wounded on Eniwetok. The other brother ended up making a career of the Army and retired after 30 years.
My working middle-class neighborhood was an influence on me, too. A number of guys in my age bracket served in the armed forces.
I read Leon Uris' book "Battle Cry" in high school; this is what steered me towards the Marines. Pittsburgh and Southwestern Pennsylvania are big Marine areas.
Jim McGurk, Carrick-Brentwood Post 725, Pittsburgh