The 2004 Grand Excursion retraced the route of the original trek, using several historic vehicles on the route. In addition to celebrating the 150th anniversary of the original event, it was used as a celebration of the reclamation of the Mississippi River. The river had become very polluted as the population of the region grew. Extensive efforts have been made to clean it up since the mid-20th century. The river remains fairly polluted, but it is much cleaner than it once was. It also celebrated the redevelopment of the riverfront areas for many communities. For many years, the riverfront area was neglected. In recent times, communities along the route have recognized the cultural importance of the riverfront, and have undertaken extensive redevelopment efforts.