Campbell entered private practice as an architect in 1975, as a consultant for the improvement or expansion of cultural institutions, including the Isabella Stewart Gardner Museum and the Boston Symphony Orchestra. He has been an urban design consultant to cities and is an advisor to the Mayors' Institute on City Design,[2] which he helped found.
In 1997 he was architect-in-residence at the American Academy in Rome. In 2002 he helped plan and appeared in a television series, “Beyond the Big Dig”.
Poet and photographer
Campbell's poems have appeared in the Atlantic Monthly and Harvard Review, among other publications. His photographs have also been published widely.