The spot where St. Ann Street dead-ends into North Rampart in New Orleans, the dividing line between the French Quarter and the Tremé neighborhood, was quiet on a Friday night in November 2005. Once alight with bulbs that spelled out “Armstrong,” the large steel archway that frames the intersection was dark, its white paint overtaken by rust. Beneath it, a thick, carelessly wound chain bound two iron gates, from which dangled a steel padlock. The whole assembly looked as if it was meant to secure some oversized bicycle rather than the entrance to a 32-acre city park modeled after Copenhagen’s Tivoli Gardens and named for trumpeter Louis Armstrong.