Study the engravings on the tombstones and try to figure out the history of the area at Longwood Cemetery. You'll find lots of fascinating stories among the monuments here.
You're spoiled for sightseeing choice when staying in Kennett Square. Longwood Cemetery is an ideal place to start here, but there are loads of other worthwhile spots to explore. Longwood Gardens, Winterthur Museum, Garden and Library, and Brandywine River Museum are not far from the burial ground and will round out your day nicely.