Our family actually has a variation on this question planned for two future summer trips of two weeks each. My oldest child’s middle name is Douglass, and he will turn ten years old in the summer of 2016. My youngest child’s middle name is Lincoln, and he will turn ten in the summer of 2020. In the summer of 2016, we will take a two week vacation visiting sites associated with Frederick Douglass, and in the summer of 2020 we will take a two week vacation visiting sites associated with Abraham Lincoln.
I cannot predict the exact sites because we will spend the preceding year letting the birthday boy choose which sites he would like to include on the itinerary.