ceremony as well as a Christmas Eve sing-along with carolers and festive music. Also, the Washington Square Music Festival, which began in 1953, has brought chamber music concerts to park-goers every summer. Protests and demonstrations In 1834, New York University decided to use prison labor to dress the stone for a new building, across from the park, as prison labor from Sing Sing was cheaper than hiring local stonemasons. This, the stonecutters of the city said, was taking the bread out of their mouths. They held a rally in Washington Square Park, and then held the first labor march in the city. That turned into a riot, and the 27th New York regiment was called out to quell the stonecutters. The regiment camped in Washington Square for four days and nights until the excitement subsided. New York University continued their use of prison labor. On Labor Day September 2, 1912, approximately 20,000 workers (including 5,000 women) marched to the park to commemorate the Triangle Shirtwaist Factory fire, which had killed 146 workers the year before. Many of the women wore fitted tucked-front blouses like those manufactured by the Triangle Shirtwaist Company. This clothing style became the working woman's uniform and a symbol of female independence, reflecting the alliance of labor and suffrage movements. Over 25,000 people marched up Fifth avenue from the park demanding women's suffrage in 1915. Notable people In 1888, Robert Louis Stevenson, visiting the U.S. to seek medical help for his battle with consumption, talked to Mark Twain in the park. In the years before and after World War I, the park was a center for many American artists, writers, and activists, including the photographer André Kertész, who photographed the square during winter. Later, the park was a gathering area for the Beat generation, folk, and hippie movements in the 1950s and 1960s; in 1958, musician Buddy Holly, a nearby resident of Greenwich Village, spent time in the park both listening to people play and helping guitarists with musical chords. On September 27, 2007, Democratic Presidential candidate Barack Obama held a rally at Washington Square; 20,000 people registered for the event, and the crowds overflowed past security gates set up as a cordon. The New York Times described the rally "as one of the largest campaign events of the year." On television and film Washington Square Park has appeared in many popular films and television shows, including