In his 1964 classic Railroads and American Economic Growth, Fogel attacked the commonly-held belief that railroad transportation was the driver of post-Civil War growth in the United States. His analysis challenged what he called the "Axiom of Indispensability," writing "no single invention was vital for economic growth in the nineteenth century." Alternatives to rail transportation existed--namely wagons and canals. When considering all the costs, his data showed the "iron horse" probably contributed around 5% of GDP.
His figures have been debated, but the wisdom of his underlying critique remains; so long as alternatives exist to fulfill material wants, can a single alternative truly be indispensable? Or as Ryan Avent wrote in the Economist "the broader lesson—that one has to think critically about the counterfactual in trying to assess technologies or shocks or economic policy—has been an indispensable one for me."
In a 2004 interview with Marika Griehsel, Fogel explained that with the study of economics "it's impossible not to be historical, you have to go back and look at the record, at least 30 or 40 years, sometimes 100 years, in order to understand the process of change."
Robert Fogel died on June 11, 2013. The image is from the University of Chicago: Robert Fogel with his wife Enid.
The Economic History Review (1969) Article by Paul David "Prof. Fogel on and off the rails"
Interview with Robert Fogel from Nobelprize.org
Robert Fogel NYT Obituary
Robert Fogel WSJ Obituary
Robert Fogel Economist Obituary