Why is the ninth month called September?
1803, "productive working" of something, a positive word among those who used it first, though regarded as a Gallicism, from French exploitation, noun of action from exploiter (see exploit (v.)). Bad sense developed 1830s-50s, in part from influence of French socialist writings (especially Saint Simon), also perhaps influenced by U.S. anti-slavery writing; and the insulting word was hurled at activities it once had crowned as praise.
It follows from this science [conceived by Saint Simon] that the tendency of the human race is from a state of antagonism to that of an universal peaceful association -- from the dominating influence of the military spirit to that of the industriel one; from what they call l'exploitation de l'homme par l'homme to the exploitation of the globe by industry. ["Quarterly Review," April & July 1831]