When it was redesigned in 1872 by Frederick Law Olmsted and Calvert Vaux, the previously fenced-in Union Square was opened “to meet the public requirement of mass meetings.” This was code for military assemblages meant to maintain social order, but, thanks to its open space and proximity to Lower East Side working-class and immigrant communities, the park soon became home to rather different gatherings. “Ones held by labor organizations or generally left-wing political groups,” explained Marci Reaven, of the New-York Historical Society. Union Square hosted the first Labor Day parade in 1882, workers’ rallies during the Great Depression, and the first Earth Day, in 1970. But in the days following 9/11, the space became the central grieving point for New Yorkers just looking to stand together. Mourners brought flowers, lit candles, and wrote messages in chalk on the ground. A vigil on Friday, September 14, brought together kids and adults, punks and professionals, who prayed and sang through the night. The communal spirit would be short-lived, however: Union Square quickly became a locus for protests against the Iraq War.