On March 24, 1916, the Indianapolis community celebrated the laying of the new Library's cornerstone. A grandstand to seat three hundred guests was built for the event. South of the grandstand, St. Clair Park formed a natural stadium for the audience. Five hundred invitations were mailed to officials and prominent citizens, including then past and present members of the Board of School Commissioners who were honored guests. A chorus of 1,000 school children, under the leadership of Edward Bailey Birge, director of music for the public schools, sang "The Messiah of the Nations," written for the occasion by James Whitcomb Riley, with music composed by John Phillip Sousa.
The new Library, built on land donated by James Whitcomb Riley, was designed by Paul Cret and built in the Greek Doric style. Construction was completed in October 1917. It was considered architecturally to be one of the most outstanding library structures in the United States.
The Cret Building interior materials include Indiana limestone, walnut and white oak. Fittingly, its exterior is of Indiana limestone built on a base of Vermont marble, with carved stone cornices adding to its beauty. A broad expanse of steps leads up to the entrance, which is framed by impressive Greek columns. The ceiling of the Simon Reading Room was painted in Pompeian style by C. C. Zantzinger and tells the history of Indiana.
The bronze gates at the Cret Building’s main entrance on St. Clair Street were purchased with pennies donated by Indianapolis school children. The inscriptions on each of the massive wrought iron gates read: The gates are the gift of the children of Indianapolis in loving remembrance of their friend James Whitcomb Riley.
Central Library expanded in 2007 with a six-story glass and steel-framed addition designed by Evans Woollen that gently embraces the Cret Building seamlessly joining the traditional and modern architecture. In 2016, Elle Decor magazine included Central Library in its list of the "50 Best Libraries in America."