Theodore Cooper

BM - Merrimack River Bridge (Essex County, Massachusetts)
designer, 1888
Pratt deck truss bridge over Merrimack River on Boston & Maine RR
Derelict/abandoned

Coraopolis Bridge (Allegheny County, Pennsylvania)
Engineer, 1893
Lost through truss bridge over Ohio River Back Channel on Grand Avenue/Ferree Street
Replaced by a new bridge

Essex-Merrimack Bridge (Oldest) (Essex County, Massachusetts)
Designer, 1792
Lost Through truss bridge over Merrimack River
Replaced by a new bridge

Federal Street Bridge (Allegheny County, Pennsylvania)
Built 1892
Lost Pennsylvania through truss bridge over Allegheny River on Federal Street
Replaced by a new bridge