True or Horseshit?

“for centuries England has relied on protection, has carried it to extremes and has obtained satisfactory results from it. There is no doubt that it is to this system that it owes its present strength. After two centuries, England has found it convenient to adopt free trade because it thinks that protection can no longer offer it anything. Very well then, Gentlemen, my knowledge of our country leads me to believe that within 200 years, when America has gotten out of protection all that it can offer, it too will adopt free trade.”

These words, attributed to Ulysses S. Grant, have been bothering me. They seem to have begun life in Andre Gunder Frank’s classic “Capitalism and underdevelopment in Latin America : historical studies of Chile and Brazil”. The quote is accompanied by the following parenthesis: “cited in Santos 1959:125 and retranslated from the Spanish by the author”. My 1969 edition, enlarged and revised, according to Monthly Review Press, contains no such reference. And, well, I’m not sure where to turn. With the uptick of Monthly Review readers and editors over here at Class Worrier, I thought I’d appeal to you, dear reader. Any thoughts on how to find out whether Grant ever said anything remotely like this?