The art deco tower, designed by architect John Torrey Windrim as an annex for Wanamaker's department store, was completed in 1932.

Until 2014, the building's bell tower was decorated on all four sides with PNB's initials in stainless steel 16 feet (4.9 m) tall.

The 24th and 25th floors originally featured a luxurious penthouse designed for Rodman Wanamaker and his wife [citation needed]; it was converted to office use in 2000 by independent advertising agency Red Tettemer O'Connell + Partners.

[9] The building's cornerstone was set on October 1, 1932, with a ceremony attended by William L. Nevin and Wanamaker executives from New York City, Paris and London.

PNB president Frederic A. Potts said, "The purchase of this building will enable the Philadelphia National Bank more adequately and efficiently to support the large-scale industrial and commercial expansion under way in this city."

[16] The building was owned by the PNB, and later its parent company CoreStates, until it was sold to the JPMorgan Strategic Property Fund in 1996 for almost US$28.5 million.

The resulting vacancy prompted the owners to renovate the building, renamed One South Broad, at a cost of US$10 million.

[14] Renovations included modernizing the elevators, security and safety systems and converting the lower floors to retail and restaurant space.

Philadelphia National Bank's renovations included the addition of granite black slabs on the street level facade.

[12][19] The 2000 renovation also created a new entrance on the building's Broad Street front, which leads to a three-story gallery lobby.

[12][19] Containing 9,000 square feet (840 m2) each, the 24th and 25th floors were used as a penthouse apartment for Rodman Wanamaker, consisting of five bedrooms, six baths, and outdoor terraces.

Until the 1970s, PNB used the sign to forecast weather by lighting the letters in red to indicate a warming trend, or green to predict the opposite.

[24] Tuned to a low D bass clef,[25] the bell's original home was the Wanamaker Building, a block from One South Broad.

The ringing of the bell, which can be heard for 25 miles (40 km), is often mistakenly assumed to come from City Hall's clock tower across the street.

[12][20] Philadelphia Orchestra conductor Leopold Stokowski wrote in 1962 that the bell had "one of the finest sounds I have heard anywhere in America, Europe or Russia".

[20] The Wanamaker's Men's Store occupied the first seven floors of the skyscraper until 1952 when the Philadelphia National Bank moved into the building.

[30] A three-story Walgreens presently occupies the site (2014) and areas of the exceptionally beautiful Wanamaker Men's Store plasterwork ceiling are visible at the upper stories.