the City". Journalist Walt Whitman characterized the streets of Manhattan as being traversed by "hurrying, feverish, electric crowds". Manhattan has been the scene of many important global and American cultural movements. In 1912, about 20,000 workers, a quarter of them women, marched upon Washington Square Park to commemorate the Triangle Shirtwaist Factory fire, which killed 146 workers on March 25, 1911. Many of the women wore fitted tucked-front blouses like those manufactured by the Triangle Shirtwaist Company, a clothing style that became the working woman's uniform and a symbol of women's liberation, reflecting the alliance of labor and suffrage movements. The Harlem Renaissance in the 1920s established the African-American literary canon in the United States and introduced writers Langston Hughes and Zora Neale Hurston. Manhattan's vibrant visual art scene in the 1950s and 1960s was a center of the pop art movement, which gave birth to such giants as Jasper Johns and Roy Lichtenstein. The downtown pop art movement of the late 1970s included artist Andy Warhol and clubs like Serendipity 3 and Studio 54, where he socialized. Broadway theatre is considered the highest professional form of theatre in the United States. Plays and musicals are staged in one of the 39 larger professional theatres with at least 500 seats, almost all in and around Times Square. Off-Broadway theatres feature productions in venues with 100–500 seats. Lincoln Center for the Performing Arts, anchoring Lincoln Square on the Upper West Side of Manhattan, is home to 12 influential arts organizations, including the Metropolitan Opera, New York City Opera, New York Philharmonic, and New York City Ballet, as well as the Vivian Beaumont Theater, the Juilliard School, Jazz at Lincoln Center, and Alice Tully Hall. Performance artists displaying diverse skills are ubiquitous on the streets of Manhattan. Manhattan is also home to some of the most extensive art collections in the world, both contemporary and classical art, including the Metropolitan Museum of Art, the Museum of Modern Art (MoMA), the Frick Collection, the Whitney Museum of American Art, and the Frank Lloyd Wright-designed Guggenheim Museum. The Upper East Side has many art galleries, and the downtown neighborhood of Chelsea is known for its more than 200 art galleries that are home to modern art from both upcoming and established artists. Many of the world's most lucrative art auctions are held in Manhattan. Manhattan is the epicenter of LGBT culture. The borough is