Warren & Wetmore, architects of the Commodore which was completed in 1919, the hotel had 1,956 guest rooms on 28 floors. The hotel at 42nd Street and Lexington Avenue claimed to have the largest banquet and ballroom in North America. It seated 3,500 and hosted many of the country's most important functions.

Below is a photo of the same South West corner of the hotel from 1918 when it was under construction. The photo shows the hotel's facade brickwork nearly completed, with just one more floor to go and the copper cornice, part of which can be seen stripped off in the above photo.

The foreground is Park Avenue and sometime after this photo an elevated "ramp" of sorts was built to take traffic up over 42nd street and around Grand Central Station between the station and the Commodore in a torturous winding path for Northbound and the same around the other side for South bound. On the North end of the station traffic was routed through a tight double curve in a short tunnel through another building that straddles and faces North on Park Avenue.