The library comes from humble beginnings, but has continued to grow and become a staple in the communities it serves. The library opened in September of 1988 as a branch of the Vassar Public Library. When a tax vote to fund the library failed, Vassar’s library board discontinued its support and closed the branch in June of 1990. The library reopened November 1st, 1990 as Unity District Library with the combined backing of the Village of Reese, Denmark Township and the determined efforts of the Friends of Unity District Library.
The library was originally open fourteen hours weekly, and was located in rental space in the former “Massoll Building” at the corner of Reese Road and Saginaw Street.  However the library continued to grow with the interest and efforts of many. In 2002, Harry and Delphine Bader, part-owners of the Bader Bros. Inc. farm-implement dealership in Reese, donated Independent Bank Corp. stock to the library “so the library could buy a building of its own” stated Harry Bader of Reese. 
The library moved from its old location to the larger location at 2065 Gates St. In the past, the building housed a coin-operated laundry and a hairstyling salon. “I knew the library could use this building to have a place they could call their own,” said Bader. In 2004, the renovation of the new building was complete. 
 After moving into the building, and with much progress in providing services, it became apparent that the library’s service area did not coincide with its legal boundaries.Research was done, and it was decided that a public school district could be a partner in a District Library Agreement. 
Consequently, the original Unity District Library Agreement was dissolved. The very same day, by virtue of votes by the Denmark Board of Trustees, Reese Village Council and the Reese Public Schools Board,  Reese Unity District Library was established. The new library’s legal boundaries incorporated all of Denmark Township, the Village of Reese, and those portions of the Reese School District not already included in another public library’s service area. These areas incorporated into RUDL were Reese Public School’s portions of Buena Vista, Blumfield, and Gilford Townships.
In 2012 an addition of a community room was completed.