The Sioux City Municipal Auditorium, now known as the Long Lines Family Recreation Center, is a 3,500-seat multi-purpose arena in Sioux City, Iowa, United States. The fifth in a line of major indoor venues built in Sioux City, it was designed by Knute E. Westerlind in 1938 and finally completed after many delays in 1950. In 2003, the building was replaced by the Tyson Events Center, built around the northeast corner of the Municipal Auditorium. The building was then converted to its current use as a recreation center.HistoryFor countless generations, the Native American residents at the confluence of the Big Sioux River with the Missouri River held their ceremonies, performances, and sporting events primarily outdoors, without need of specialized structures. The fourth Treaty of Prairie du Chien in 1830 forced them to leave Iowa, and forty years later the new White residents built the first in a series of five major indoor venues for Sioux City: the Academy of Music of 1870, the Peavey Grand Opera House of 1888, the Old Municipal Auditorium of 1909, this one completed in 1950, and Gateway Arena of 2003.The Academy of Music was located between Pierce and Douglas Streets on the southern side of Fourth Street. Designed by local architect H.O. Ball and erected by the firm of Sharp and Beck, it employed cast iron columns, a brick exterior, and terra cotta. The first floor included the city post office and commercial space, with an 800-seat performance space on the second floor. As the city's only large hall, it held high school graduations, theatrical performances, concerts, and speeches, including at least two by Susan B. Anthony speaking on behalf of women's suffrage. The building ended its life as part of the growing Davidson Brothers Department Store, and was demolished in 1910 to make way for a better structure for the store.