Later in the 20th century, when the city's rail service had declined to its current level of one commuter route, the building's interior was closed.

[1] On the east (front) facade of the main block are three two-story round-arched window openings, filled in near the top where a new floor was later added.

On the north wing's east facade, windows have been added to the previously blind arch portion to provide illumination for the second story.

On the west of the south wing is a gabled remnant of the original platform shelter, supported by iron trusses on center posts and cables from the building.

These tiles are the same used at the Boston Public Library, Ellis Island, Grant's Tomb, the Biltmore Estate and other architecturally significant buildings.

The window surrounds have similarly lavish decorations as the exterior, with two bands of terra cotta separated by dentils done in leaves and pearl molding.

The buff brick walls likewise has a dentilled cornice with an engaged baluster-and-ring turning and a wide cyma molding done in a stylized floral pattern.

They include brass ticket windows, a long Mission style wooden bench, iron radiator grill and marble baseboards and sills.

[1] In the early years of the 20th century, the city of Waterbury, then prosperous and growing, began working with the New Haven and other railroads serving it on an urban renewal program to clear the way for a newer, larger station they all needed.

[4] McKim, Mead & White's design, extravagant in size and decoration, was meant to symbolize the city's prosperity and the railroads' importance to it.

The firm's design is different from its typically academic style in its efforts to unite the interior and exterior through similar materials and decorative themes, as well as the vaulted ceiling echoing the arches of the windows.

The light reflecting off the warm interior colors through the large arched windows of the main facade made the building particularly welcoming at night.

[1] A year after construction began, the president of one of the railroads asked for a clock tower, given Waterbury's proximity to the Seth Thomas plant.

A few years later, the American Brass Company, representing another industry identified with the city and region, built new headquarters across Meadow Street from the station.

[9] At that time the south wing was still being used by Metro-North commuter rail passengers as a waiting area; since then that portion of the interior has been closed off and a new platform built.