The 33rd Street station was constructed for the Interborough Rapid Transit Company (IRT) as part of the city's first subway line, which was approved in 1900.

The original station interior is a New York City designated landmark and listed on the National Register of Historic Places.

[6]: 21  However, development of what would become the city's first subway line did not start until 1894, when the New York State Legislature passed the Rapid Transit Act.

It called for a subway line from New York City Hall in lower Manhattan to the Upper West Side, where two branches would lead north into the Bronx.

[6]: 161  The Rapid Transit Construction Company, organized by John B. McDonald and funded by August Belmont Jr., signed the initial Contract 1 with the Rapid Transit Commission in February 1900,[7] in which it would construct the subway and maintain a 50-year operating lease from the opening of the line.

[5]: 4  Belmont incorporated the Interborough Rapid Transit Company (IRT) in April 1902 to operate the subway.

To accommodate a never-built connection to the mainline platforms at Grand Central Terminal, the tunnel carrying northbound trains was shifted eastward (nearly touching the eastern curb line of Park Avenue).

[12] After Shaler was killed by a rockslide in his own excavation site on June 17, 1902,[13] his estate completed the construction of the tunnel between 33rd and 41st Street.

[2][6]: 186  Litigation over the IRT's Murray Hill tunnels continued for several years;[8]: 7–8  in 1905, a judge found that the city government was responsible for the January 1902 explosion.

[17] To address overcrowding, in 1909, the New York Public Service Commission proposed lengthening the platforms at stations along the original IRT subway.

[18]: 168  As part of a modification to the IRT's construction contracts made on January 18, 1910, the company was to lengthen station platforms to accommodate ten-car express and six-car local trains.

New "electric manholes", passageways leading to the equipment closets, were built at the southern ends of the platforms.

[20] In December 1922, the Transit Commission approved a proposal to convert the 33rd Street station into an express stop.

[23][24] Local business owners supported the proposal,[25][26] but the IRT opposed the plan, which would cost the company $750,000.

[32][33] In 1928, to alleviate overcrowding on the Lexington Avenue Line, a consulting engineer for the New York State Transit Commission proposed the construction of "reservoir" stations at 33rd/34th and 42nd Streets.

[4]: 3–4 [5]: 4 [45]: 9  The ceiling height varies, being about 15 feet (4.6 m) above platform level near the northern fare control areas, and lower in other portions of the station.

The platform walls are divided at 15-foot (4.6 m) intervals by buff and green mosaic tile pilasters, or vertical bands.

These are composed of fourteen bronze loops surrounding the I-beam columns near the northern fare control areas, which are designed as handholds or seat rests.

[48][49][50] According to Garvey, "the thick bronze bar ... resembles the lasso demonstration in a Will Rogers film clip".

[49] Garvey subsequently designed Lariat Tapers, a similar artwork at the Wall Street station, in 2011.

[4]: 4 [52] The street staircases contain relatively simple, modern steel railings like those seen at most New York City Subway stations.