My (still-living) father was in the US Navy, where he attained the rank of chief petty officer; he was mostly in anti-submarine warfare aboard P3 Orions with a deployment in 1980 aboard the USS Dwight D. Eiesenhower.
Both of my grandfathers were in the US Army in WWII; my maternal grandfather landed in Europe not long after D-Day and he was with the Allied army that crossed the Rhine in March of 1945 (and his brother David enlisted in the Coast Guard at the age of 17).
My great-grandfather William Childs served with the Allied Expeditionary Force in France in WWI.
My 3rd great-grandfather Samuel Coomes of Washington, DC enlisted in the 6th Battalion, District of Columbia Infantry, 4 days after Fort Sumter.
My 3rd great-grandfather Coleman C. Adams enlisted in the 15th Regiment, Kentucky Cavalry (Union) and served for one year.
My 5th great-grandfather Paul French was captain, major and lieutenant colonel of the 5th Regiment of Indiana Militia in the War of 1812 before resigning his commission in 1813.
My 5th great-grandfather William Handy was a captain in the Worcester County, Maryland, militia in the Revolution (his brother Samuel Handy was a colonel, a member of the Maryland House of Delegates, and a member of the state constitutional convention in 1776).
My 6th great-grandfather Samuel Abell was a major in the St. Mary's County, Maryland militia and a member of the Committee of Safety.