Built in 1893 and opened in 1894, Salem School was a gift to the town from industrialist John Howard Whittemore, who funded its construction and commissioned the renowned architectural firm McKim, Mead & White for its design. The design of the school has been attributed to William Rutherford Mead, the eldest of the three partners at McKim, Mead & White. Positioned at the head of the Naugatuck Green, the school is a prime example of Second Renaissance Revival architecture, reflecting Whittemore’s vision for elevating the town’s aesthetic landscape.

The brick building rests on a high rusticated brownstone foundation, with an H-plan layout featuring a gabled main block and hip-roofed pavilions framing a recessed entrance court. A round-arched brownstone doorway and a central cupola crown the slate roof, emphasizing the building's classical details. The ‘H’ style plan permits windows on three sides of every classroom, allowing for better natural light and air circulation.

A bracketed stone balcony is situated above the entrance, reinforcing the axial symmetry of the building. A stone nameplate, centered above the balcony and French doors, further enhances the architectural prominence of the entrance.

The building commemorates Naugatuck's early name, "Salem Bridge," with the dates over the entrance—1773, indicating the town's first school building, and 1893, the year this school was constructed.

Salem School replaced the Union Center School, originally located on the Green. Adjacent to Lewis Park, donated to the town in 1894, the site further enriches the civic area.

The location for the school was donated to the Union School District in 1875 by George A. Lewis, and the H. Wales Company built it at a cost of $71,290.

Designated as part of the Naugatuck Center Historic District on July 30, 1999, the site was officially listed on the National Register of Historic Places on November 3, 1983.