Complex sentence: On the weekend of July 19,1996, Revere commemorated the centennial of the first opening of Revere Beach with a three-day celebration, and on July 26,2004, Revere Beach was designated a National Historic Landmark.
Split into simpler sentences: On the weekend of July 19,1996, Revere commemorated the centennial of the first opening of Revere Beach with a three-day celebration. On July 26,2004, Revere Beach was designated a National Historic Landmark.