Throwback Thursday – Independence Hall Made with “Conshohocken Blue” Marble

What is now Sherry Lake was once called Potts Quarry and marble from the quarry, known as Conshohocken Blue, was used in the building of Independence Hall.

Sherry Lake
Today the quarry is filled with water and is known as Sherry Lake.

Limestone is abundant in the western suburbs of Philadelphia. From a the website:

The pseudo-marble from southeastern Pennsylvania has garnered many names based on its supposed origin. “King of Prussia marble,” “Conshohocken blue,” and “Schuylkill gray” all derive from locations of quarries within the limestone belt crossing three counties that surround the city of Philadelphia. This extensive limestone deposit begins in Montgomery County, which is just north of the city, and crosses the Schuylkill River to the southwest extending through Chester and Lancaster counties. The length of the limestone belt is fifty-eight miles, and the widest section is three miles (fig. 2). The most productive quarries were only a few miles outside the city limits, and the names of towns near them became associated with the stone. Conshohocken and King of Prussia, for example, are situated along the Schuylkill River, which flows past the western edge of Philadelphia.

How did the quarry get filled with water? Based on a blog post from a former resident of Sherry Lake Apartments, who did a lot of research on the former quarry, an “old guy” told him the quarry workers struck a natural underground stream.

If you google “Conshohocken Blue” and “Independence Hall” you will find other references to two other nearby quarries as being a source of marble for Independence Hall. One quarry was located off Colwell Lane between 2nd and 4th Avenues. The other is described as being two miles northeast of the Borough. That sounds like the quarry off Conshohocken Road. Whether they all provided marble or history has forgotten the actual source, it does sound like some Conshohocken Blue was used at Independence Hall.

So next time you are at Independence Hall, try to spot the Conshohocken Blue.