What is the importance of Archduke Franz Ferdinand's gravesite in the novel, An Abundance of Katherines?

The assassination of the Archduke Franz Ferdinand is what sparked World War I. When Hassan and Colin are driving in Tennessee, Colin sees an exit for the grave of the Archduke, so the boys pull off to take the tour. Toward the end of the novel, Colin anagrams the letters of the Archduke's name on the gravestone to determine it is really the grave of Lindsey Lee Wells great grandfather. Hollis made up the fact that it is the Archduke so they can sell tour tickets and raise money.