Development of this area was associated with soap manufacturing that was established on an industrial scale in Cambridgeport in the early 19th century. 

The first soap factory began in 1804 as a profitable way of disposing of tallow, a byproduct of the slaughterhouses that had been established in Cambridgeport after the opening of the West Boston Bridge (what is now the Longfellow Bridge, also known colloquially as the Salt and Pepper Bridge). 

One of the largest soap factories was owned by Charles Valentine, a very wealthy Cantabrigian who lived in a magnificent house on Prospect Street (now the site of Whole Foods) and who was also engaged in the wholesale provision and beef packing businesses. In 1828 he established a soap and candle manufactory that covered most of the block between Pearl and Brookline on the south side of Valentine Street, which was then a fairly isolated area of Cambridgeport. By the 1880s it was producing 10 million pounds of soap a year.* Between 1835 and 1841, Valentine built at least three double workers’ cottages as housing for his employees, at 5-7 Cottage Street and 95-97 and 101 Pearl Street, convenient to the factory but several blocks north of its noxious fumes. The provision of factory housing was unusual in Cambridgeport, but the double workers’ cottage form of Valentine’s houses became quite common in the area in the first two thirds of the 19th century.