Answer: You guessed it, a sugar refinery. 

The Pennsylvania Sugar Refining Company, which once stood on the industrial shores of East Philadelphia at the end Shackamaxon Street, was the nation's last independent producer of sugar. Once known to many in Philadelphia as the "Sugar House," it was bought by the National Sugar Refining Company (NSRC) in the 1940s and became the location of its Pennsylvania division. During the first half of the century, the Sugar House’s presence in the neighborhood and the city as a whole expanded—while it employed about 40 men throughout the 1880s, by the 1950s it employed over 1500 men and women. During World War II, it produced a whopping 408,000 tons of refined sugar. The refinery remained in operation until the NSRC sold the property in 1984.

Among HSP's manuscripts are a small assortment of records from the Philadelphia Sugar Refining Company (Am. 343), as well as "A Record of the Behavior of the Men and Machines in the Pennsylvania Sugar Refinery, 1868-1960" by Dan Gutleben (Am. 3434). Our library also has publications on the company as well as the history of sugar production in Philadelphia.

An expanded version of this article appeared in the 3/29 Currents section of the Philadelphia Inquirer.