On September 11, 2001, Shanksville, Pennsylvania, became a center of national attention when United Airlines Flight 93 crashed into a former strip mine in sleepy Somerset County, killing all forty passengers and crew aboard. This is the story of the memorialization that followed, from immediate, unofficial personal memorials to the ten-year effort to plan and build a permanent national monument to honor those who died. It is also the story of the unlikely community that developed through those efforts.

As the country struggled to process the events of September 11, temporary...