1850 (approx) Operated by the Seneca Sandstone Company. 2
1867 Operated by the Potomac Red Sandstone Company. 2
1870 The greatest number of men employed by the quarry and mill. 3
1871 The canal transported 850,000 tons of stone. 3
1891 Operated by the Seneca Stone Company 2
1893 Seneca Stone Company paid $833.33 for the use of waterpower from the canal. 1
1900 Quarry operations were stopped. 1
ACHS Summary Form
1: The Smithsonian Journal of History, Vol. III, Spring 1968, pp 41-58
2: Landmarks Research Form by Bob Kasparek
3: Seneca Creek Sandstone: Its History and Use as a Building Stone by Kristin Fetzer, 1997
4: Building stones of our nation's capital U.S. Geological Survey
In 1871 the canal transported 850,000 tons of stone.
Seneca Quarry & Time Line Cont.