Queen Elizabeth Visits Manhattan 1957 - Found Photo
In October 1957, a young Queen Elizabeth II visited New York and the United Nations. In this photo crowds gather on Park Avenue in hopes of a glance at the Queen. I believe the Queen's car is the silver vehicle with the tail fins. This is the same vehicle seen in the photo taken on Broadway during the parade.
My Thanks to Lynne (Lynne's Lens') for identifying the event. Please visit her wonderful photostream.