The 'classroom' link is the one that led me to the question.
The wikipedia link says that Karl Marx referred to Carey as the "only American economist of importance" and described Carey's theories as the chief obstacle to communist revolution in the United States. He pledged to wage "hidden warfare" against Carey.
Yes, its a dry subject but I'm surprised (having read about him) that Carey isnt better known.
“The honest man, tho' e'er sae poor,
Is king o' men for a' that” Robert Burns