Work begins this weekend on one of America's newest national parks. The families of the people aboard Flight 93, which went down in Somerset, Pa., in the Sept. 11 attacks, will gather at the crash site today for the ceremonial groundbreaking.

America's national parks preserve our most sacred natural spaces, such as Yosemite and the Grand Canyon, as well as important pieces of our national history such as the battlefields at Gettysburg. Construction of the first phase of the Pennsylvania memorial is scheduled to be completed in time for a dedication ceremony on the 10th anniversary of the 2001 attacks. The Flight 93 memorial will be the only Sept. 11 site designated as a national park, which means that every citizen will be a part owner and steward of this monument. Since Sept....