- Gift - From the family of J. Herman Bosler.
- Plans - Began after Mr. Bosler's death in 1897.
- Architects - Baldwin & Pennington of Baltimore.
- Local Contractor - A. H. Brindle.
- Architectural Style - Colonial with Ionic Columns at entrance.
- Interior Woodwork - Quartered oak with Georgia pine floors
- Lobby - Mosaic tile in five colors of footboards of marble.
- Dome - Stained glass window accent.
- Fireplaces - Both have light green tiles bearing an olive wreath and torch.
- Opening Date - January 19, 1900.
- Stained glass window in the original building.
- Memorial to Miss Lila McClellan Bosler, daughter of Mr. J. Herman Bosler. Reproduction of the painting "Hope" by Sir Edmund Burne-Jones.
- Executed by Maitland-Armstrong Company.
- Placed by C.D. Rudy of Harrisburg.
The addition of the West Wing and connecting ramp and stairs was completed on May 2, 1987. It added the needed space to Bosler Library. When it opened in 1987, only the first floor was utilized. The Children's Department was located in a small room with a bay window looking out on the rest of the area. The Children's Library, as we know it today, was opened on April 13, 1994. This expanded space is on the second floor of the West Wing.
Today, Bosler has 17,540 square-feet of space dedicated to serving the residents of Carlisle Borough, Dickinson Township, Lower Frankford Township, Middlesex Township, North Middleton Township, South Middleton Township, and West Pennsboro Township.