Always interesting to hear about stuff like that:
My paternal grandfather served in WWI with the U.S. Army in Belgium.
My maternal grandfather served in WWI with the Russian army until Russia capitulated.
My father served in WWII with the Signal Corp (attached to the Air Force) from D-Day until the end of the war.
I have an uncle who was among the first U.S. troops on Omaha Beach. He was with the engineers.
I lost a cousin in Vietnam.
I have a brother -in-law who did 3 deployments in the Iraq War.
I have a nephew in the Air Force who just recently returned from a deployment in Afghanistan.