Hagley Museum near Wilmington in New Castle County, Delaware — The American Northeast (Mid-Atlantic)
Rocks
The stones that make up the roll mill you are standing in are Brandywine blue gneiss, ("nice"). This metamorphic rock is harder than granite. This makes blue gneiss a perfect building material for structures housing large, industrial equipment while withstanding the force of potential explosions. These rocks are unique to this region and were quarried on site. they were used for everything from roll mills to mill race walls to the du Pont family home.
Erected by Hagley Museum and Library.
Topics. This historical marker is listed in these topic lists: Industry & Commerce • Natural Features • Natural Resources.
Location. 39° 46.658′ N, 75° 34.438′ W. Marker is near Wilmington, Delaware, in New Castle County. It is in Hagley Museum. It can be reached from Hagley Creek Road north of Blacksmith Hill Road, on the right when traveling north. Touch for map. Marker is at or near this postal address: 300 Hagley Creek Rd, Wilmington DE 19807, United States of America. Touch for directions.
Regionally, this marker is in Greater Philadelphia. It is also in the
this page online
Other nearby markers. At least 8 other markers are within walking distance of this marker: Sourcing Materials (here, next to this marker); Water (here, next to this marker); The DuPont Company Grows Quickly (here, next to this marker); Beyond the Brandywine (here, next to this marker); Trees (a few steps from this marker); The Hagley Story / The du Pont Story (a few steps from this marker); Natural Resources (a few steps from this marker); Victor du Pont (a few steps from this marker). Touch for a list and map of all markers in Wilmington.
Credits. This page was last revised on June 29, 2026. It was originally submitted on April 28, 2025, by Devry Becker Jones of Washington, District of Columbia. This page has been viewed 108 times since then and 12 times this year. Last updated on June 28, 2026, by Carl Gordon Moore Jr. of North East, Maryland. Photos: 1, 2. submitted on April 28, 2025, by Devry Becker Jones of Washington, District of Columbia.
