Constructed in 1911-1913, the Newark Post Office was designed by James Knox Taylor, Supervising Architect of the Treasury Department (between 1897 and 1912). The Newark PO it is one of 13 post offices included in a thematic nomination designed by Taylor. This Classic Revival building, with its exterior stucco finish, is unique among Taylor's work. On the interior, the public lobby features a terrazzo floor, bordered with white marble trim and white marble baseboards. At a height of approximately 11 feet, the walls are paneled with oak.

The Maple Court site was acquired in 1910 for $10,000, and the building was completed in 1913 with construction costs totaling $39,987 – keeping under the total governmental appropriation for this building under the $50,000 which was authorized for site acquisition and construction. In 1938-39, a large rear wing was added to the building - $100,000 being authorized for the addition.