Wrong! This revisionist piece of economic history comes from Jonh Nye, whose new book War. WIne, and Taxes is forthcoming from Princeton University Press (thanks to Marginal Revolution for the reference). Take a look at the graph below, which shows average tariffs in Britain and France during the 19th century.
Even though trade protection comes down rapidly in Britain, it lies above that in France--an alleged foot-dragger in trade liberalization--for most of the century. Nye writes:
the example of Britain and France in the 1800s challenges us to rethink and reanalyze the relationship between trade policy and growth. The story of Britain and France shows how easy it is to be misled by the fables of conventional wisdom.