I know Memorial Day is as much about the start of summer, an extra day off of work, and cookouts as it is about fallen soldiers. I find nothing wrong with that. Hope you could enjoy the day. On a more serious note the origins of the holiday go back to the end of our Civil War. From the History Channel.
Here are the Civil War cards from one of my favorite modern non-sports sets, The History of the United States issued by Upper Deck in 2004.