According to The Philly History Blog, William Bucknell founded the Chester Gas Company in 1856, just ahead of the Industrial Revolution.  His investment would make him part of a new class of wealthy industrialists inhabiting Philadelphia and clustering around Rittenhouse Square.  By the 1860s, Bucknell would parlay his wealth into a massive residence at the Northeast corner of 17th & Walnut.  His exploits would also earn him the nickname “The Gas King.”  The image below, taken from G.M. Hopkins’ 1875 Philadelphia Atlas, shows the location of the Gas King’s home.

The Bucknell residence, 1875

During his time as a resident of Rittenhouse Square, Bucknell achieved immortality in 1881 by stepping in and saving the University of Lewisburg from financial ruin.  According to the Philly History Blog, Bucknell donated $50,000 to the school’s preservation, prompting its grateful board of trustees to rechristen it as Bucknell University.  Though Bucknell would live to see this honor in 1886, he would pass away a few years later in 1890.  His estate remained intact for a few decades beyond, as shown below in a Bryn Mawr College photo from 1900.

Bucknell’s house minus Bucknell, 1900

According to the Free Library of Philadelphia, the mansion would be demolished after the turn of the century, making way for a 14-story luxury apartment building in 1907.  By the 1940s, according to the Works Progress Administration’s 1942 Land Use Maps shown below, the apartment building was called Hotel M. 

Hotel M, 1942

Hotel M is also shown in the 1949 image here, taken from the Free Library of Philadelphia.

Hotel M, 1949

By 1970, the hotel had changed hands once again, becoming the Latham Hotel.  Today, the Latham claims to be “the standard for excellence among Philadelphia boutique hotels with its period charm and modern accommodations.”

Latham Hotel, 2014