An example of a relatively early use of the expression in print comes from  
the entry on Socialism in The American Cyclopedia, edited by George Ripley  
and Charles Dana and published by D.Appleton and Co. (New York, 1873-76):  
  
"[Proudhon proposed] that each citizen should unite in his own person the  
four necessary factors of production: laborer, capitalist, merchant, and  
employer" (p. 142).  
  
About the same time, The Living Age reprints an article from The Economist,  
where a close expression "factor in production" is used:  
  
 "[I]t is natural to ask, has the other factor in production fared equally  
well -- has the labourer been benefited as much as the capitalist"?" (The  
Living Age, Volume 120, Issue 1552, March 7, 1874, p. 635).  
  
You can get more returns searching the American Memory collection, but there  
seem to be no hits pre-dating these examples.  
  
Yuri Tulupenko