It is one of Hartford's most notable examples of the Neoclassical architectural style, which was commonly used for public buildings during the early twentieth century.

Architectural Forum cited the building as an example for private architects to follow when completing Public Works Administration commissions.

[2] Major interior renovations to the federal building occurred in 1964 and 1978 after the courts and post office vacated the location.

In 1982, the federal government renamed the building to honor Congressman William R. Cotter, who represented the First District of Connecticut from 1971 until his death in 1981.

The architects adopted traditional classical architectural forms while abandoning excessive interior ornament in favor of Art Deco's more stylized decorative components.

[2] The three-story federal building is situated on a trapezoidal block bounded by High and South Church streets and Foot Guard and Hoadley places in downtown Hartford.

Limestone pilasters separate each bay on the central section, which features a projecting cornice topped with decorative cresting.

Projecting pavilions, each containing two modified, Corinthian order columns, frame the two principal entrances located at each end of the High Street elevation.

The quotation is divided by low-relief figures on horse-back transferring a message, recalling the Pony Express and early postal delivery methods.

Pairs of engaged black marble columns with aluminum ribs and stylized Doric order capitals flank two murals at each end of the corridor.

The corridor ceiling contains recessed, framed beams bearing medallions with depictions of George Washington, Thomas Jefferson, Benjamin Franklin, and Abraham Lincoln.