The Manhattan Easter "Parade" along Fifth Avenue dates back to the 1870s, when it started spontaneously as churchgoers left mass. The annual promenade still retains its festive spirit of spontaneity—it's not a formal parade with floats and banners, just an opportunity for everyone to gather on Fifth Avenue in their Sunday best. Over the years, the attire has gotten increasingly creative, with elaborate bonnets evolving into marvelously over-the-top Easter-themed costumes.

According to the Wikipedia entry for the Easter Parade, the event started "as a spontaneous event in the 1870s... and became increasingly popular into the mid-20th century—in 1947, it was estimated to draw over a million people... By the 1880s, the Easter parade had become a vast spectacle of fashion and religious observance, famous in New York and around the country. It was an after-church cultural event for the well-to-do—decked out in new and fashionable clothing, they would stroll from their own church to others to see the impressive flowers (and to be seen by their fellow strollers). People from the poorer and middle classes would observe the parade to learn the latest trends in fashion."

On Sunday, photographer Tod Seelie checked out the scene up and down the avenue; click through on his photos for an Extreme Easter Immersion. For the full effect, listen to Irving Berlin's classic song, "Easter Parade" as you gawk.