Isabella Furnace was a cold blast charcoal iron furnace located in West Nantmeal Township, Pennsylvania. The furnace was named for Isabella Potts, wife of one of the partners, a member of the Potts ironmaking family. Isabella was the last iron furnace to be built in the county, in 1835, and was operated by members of the Potts family and their partners until 1855, when they lost control of it in a bankruptcy. It returned to the family in 1881, when it was purchased by Col. Joseph Potts (nephew of Isabella), who modernized it. The furnace, the last to operate in Chester County, went out of blast in 1894, a few months after Col. Potts' death, but remained largely intact until after his son's death in 1943. The remains of the furnace complex have been listed in the National Register of Historic Places since 1991.
History
The original operators of the furnace were Henry Potts and his brother-in-law (and second cousin) John Potts Rutter, who bought a tract of land from Robert Wilson on April 1, 1835 for the furnace site. The land was along Perkins Run near where that stream emptied into the East Branch Brandywine Creek. The tract already included a fulling mill and a sawmill, and the transaction encompassed water rights to dam Perkins Run to power the furnace. The Potts and Rutter families were already extensively involved in the iron business in the vicinity of Philadelphia; Henry's father Joseph was a partner in Glasgow Forge, on Manatawny Creek near Pottstown, Pennsylvania, and Henry was involved in ironmaking there and at Warwick Furnace, owned by his first cousin David Potts, Jr. The furnace was completed by the end of the year and named in honor of Henry's wife Isabella, née Hitner. It proved to be the last sizable furnace erected in northern Chester County.
In the spring of 1836, Henry's brother David, formerly the owner of Springton Forge, was brought in as a partner and manager of the furnace. Henry retained a half interest and David and John each a quarter interest in Isabella Furnace. Ore from the furnace was obtained from the Jones and Warwick mines nearby. These mines were operated by a partnership including members of the allied Potts, Rutter, and Brooke families. In 1839 and 1840, respectively, Henry and David's brothers Robert Smith Potts and Joseph Potts were brought into the partnership. Ultimately, David bought out most of the family interest, except for a moiety held by his nephew, William A. Smith. David's nephew Charles Follen McKim, later an architect, was born at Isabella in 1847. The furnace was well-run under David's direction, and in 1850, produced of iron per year. The furnace was converted to a forge in 1853. However, changing conditions in the iron market in the mid-1850s badly damaged David's financial position. Isabella Furnace was assigned to Robert Smith Potts and Addison May, who sold it in the following year to John Irey and James Butler.
Irey was a carpenter who, like David Potts, had made iron at Springton Forge. Under the new owners, the output of the forge in 1856 was of blooms. Irey bought out Butler in 1860 and thereafter operated the forge himself. During the early years of the Civil War, the East Brandywine and Waynesburg Railroad was built along the East Branch of the Brandywine on its way from Downingtown to Waynesburg, now Honey Brook. Its Wyebrooke station was about a half-mile south of the forge and provided a rail outlet for its products. The forge was remodeled in 1864 and it was presumably then that it became a furnace again, but Irey's operations during the Civil War were not profitable.
He sold out in 1865 to the brothers Bentley H., William D., and Horace V. Smith, members of an ironmaking family associated with Joanna Furnace and the mines around Warwick. William D. and Horace V. Smith were particularly associated with the management of the furnace until 1881. About 1870, as the Wilmington and Reading Railroad built through the region on the way from Wilmington, Delaware to Birdsboro, Pennsylvania, it established a station called "Isabella" about a mile northwest of the furnace.
In 1880, a new figure appeared upon the scene: Col. Joseph D. Potts (1829–1893), son of David Potts. Raised at Isabella Furnace, he regarded it as home. Potts made a fortune in the railroad and transportation industry, in the employ of the Pennsylvania Railroad and elsewhere. When he retired from that business, he desired to return to the property where he had been raised and become an ironmaster, like so many of his family before him. He won over the Smith brothers, who were reluctant to sell, and closed on the property on February 28, 1880.