[2] After leaving the Columbia faculty, he became director of historic preservation at the private architecture and planning firm, Beyer Blinder Belle.
He led the fight that prevented the construction of an expressway through SoHo, to save the buildings at what is now the South Street Seaport.
The James Marston Fitch Foundation, established in his honor in 1988, awards $25,000-dollar research grants for historic preservation.
The activist Jane Jacobs considered that Fitch "was the principal character in making the preservation of historic buildings practical and feasible and popular.
"[3] Dr. Fitch was awarded the Historic Districts Council's 1998 Landmarks Lion award in recognition of his lifetime of contributions to the historic preservation movement in New York City and beyond.