When Dow Chemical acquired the Philadelphia-based specialty chemicals company Rohm and Haas in 2009, it took on more than a business — it inherited a century of local history, a landmark building on Independence Mall, and a workforce deeply tied to the city. More than fifteen years later, that legacy still shapes how Dow operates in Philadelphia and how it engages with the surrounding community.
A Philadelphia Institution From the Start
Rohm and Haas was founded in 1909 and built its identity around Philadelphia from the beginning. The company grew into a Fortune 500 chemical manufacturer known for specialty materials — including acrylics like Plexiglas, emulsions, and performance chemicals — that served industries from construction to electronics to transportation. By 1999, following a merger with Morton International, Rohm and Haas had become the world’s largest specialty-chemical company, employing thousands across the Philadelphia region.
An Iconic Building on Independence Mall
Rohm and Haas’s connection to the city is written into its architecture. In the late 1950s, the company became the first private business to invest in the newly cleared Independence Mall area, choosing the corner of Sixth and Market Streets over a suburban campus in Fort Washington. The resulting nine-story building, designed by Pietro Belluschi and completed in 1964, was praised by city planners as a model for urban redevelopment and remains notable for its translucent, corrugated Plexiglas sunscreens — a fitting nod to one of the company’s signature products. According to a widely repeated account, company leader Otto Haas justified the decision to stay downtown by arguing that if companies like his abandoned the city, Philadelphia itself would not survive.
The Dow Acquisition and Its Terms
Dow’s $15.3 to $18.8 billion acquisition of Rohm and Haas in 2009 came with specific commitments to Philadelphia. Dow pledged to preserve the Philadelphia headquarters and to retain the Rohm and Haas name, a promise that was publicly welcomed by John Haas, son of company co-founder Otto Haas, as a tribute to the company’s employees and leadership over the decades. Dow went further by establishing an advanced materials business unit at the Philadelphia headquarters and adding two Rohm and Haas directors to Dow’s board, steps intended to preserve continuity in the company’s culture and assets even as it became part of a much larger global organization.
A Legacy That Still Shapes Dow’s Culture
The influence of Rohm and Haas hasn’t simply faded into Dow’s broader corporate structure. The company’s historical emphasis on scientific excellence and collaborative problem-solving continues to influence the culture at Dow’s Philadelphia site today. While Rohm and Haas is no longer an independent operating entity, its legacy of innovation lives on within Dow’s performance products and advanced materials divisions, and the Philadelphia site continues to serve as a key innovation hub for research, development, and manufacturing functions tied to those legacy product lines.
Dow’s Ongoing Presence in the Region
Beyond its operational footprint, Dow maintains an active civic presence in the greater Philadelphia area, known regionally as the Delaware Valley. The company has been recognized as a recipient of the Civic 50 Greater Philadelphia award, which honors civic-minded businesses using their time, talent, and resources to drive social impact locally. Dow’s regional strategy focuses on partnerships that serve the communities where its employees live and work, supporting equitable access to STEM and skilled trades careers, disaster resiliency, and broader community-identified needs.
Why the Story Still Matters
The Rohm and Haas story offers a rare example of a major corporate acquisition that didn’t erase the identity of the company it absorbed. Instead of relocating operations or dissolving the brand, Dow chose to keep both the headquarters and the name intact — a decision that continues to be reflected in how the Philadelphia site operates today, even as it functions as one piece of a much larger global chemical company.
Join The Discussion
Corporate acquisitions don’t always preserve local history the way Dow’s handling of Rohm and Haas did, which makes this a particularly interesting case study in how a company’s legacy can persist through ownership changes. If you’re familiar with Rohm and Haas’s history in Philadelphia — whether through work there, the Independence Mall building itself, or the broader chemical industry — what stands out most to you about how that legacy has been preserved? And for those interested in corporate history more broadly, do you think this kind of continuity is becoming more common, or is it the exception to the rule?
