From a Times Bulletin article printed July 8, 2016:
The doors first opened on March 3, 1916, and the first patron to check out a book was A.A. Auber; it was about agriculture. At that time, the library had a staff of three employees – Miss Smith, the librarian; Miss Vivian Jackson, the assistant librarian; and A.V.R. Mott, the shipping clerk. 
From the library's history page:
The new library was open for business on March 3, 1916 with 4000 books. The building was constructed of fireproof and slow burning materials, French gray pressed brick and Indiana Bedford stone with a green tile roof. Architects were Howard and Merriam of Columbus, Ohio.