Detroit Public Library  The Detroit Public Library is the second largest library system in the U.S. state of Michigan by volumes held (after the University of Michigan Library) and is the 21st largest library system (and the fourth-largest public library system) in the United States. It is composed of the Main Library on Woodward Avenue, which houses the library's administration offices, and 23 branch locations across the city. The Main Library is part of Detroit's Cultural Center Historic District listed in the National Register of Historic Places adjacent to Wayne State University campus and across from the Detroit Institute of Arts. Designed by Cass Gilbert, the Detroit Public Library was constructed with Vermont marble and serpentine Italian marble trim in an Italian Renaissance style. His son, Cass Gilbert, Jr. was a partner with Francis J. Keally in the design of the library's additional wings added in 1963. Among his other buildings, Cass Gilbert designed the United States Supreme Court Building in Washington, DC, the Minnesota State Capitol and the Woolworth Building in New York City. A stand-alone public library in Detroit dates back to 1865. An 1842 state law requiring the Detroit Board of Education to open a library resulted in a public reading room opening on March 25, 1865 in the old Capitol High School at State and Griswold Street. In 1872, the Centre Park Library opened across the street from the current location of the Skillman Branch in downtown Detroit at Gratiot and Library Street. The first branch library opened in 1897 when the Detroit Water Commission library was opened to the public; in 1905 this library was turned over to the Detroit Library Commission. Several additional branches opened shortly afterwards, including one in the Old Main building of Wayne State University. But it was not until 1910 when Andrew Carnegie, the great American library philanthropist of the early 20th century, donated funds did Detroiters decide to build a larger central library to supplement Centre Park. Property near Woodward and Kirby was purchased and in 1912 Cass Gilbert was commissioned to construct his design of a three-floor, early Italian Renaissance-style building. Due to delays and World War I, the Main Library did not open until March 21, 1921. It was dedicated June 3, 1921. In 1937, the Detroit Public Library hired its first African-American librarian, Marjorie A. Blakistone; Blackistone worked throughout her career to expand the library's African-American literature collection. The library system's bookmobile service began in 1940. After World War II, Detroit Public Library obtained "projected books" on microfilm and loaned these with portable projectors to disabled veterans (and other patrons with disabilities) who could press a switch under their chin more easily than turning a page.