In his essay "Nature" (1836) Ralph Waldo Emerson observes "Nature, in the common sense, refers to essences untouched by man; space, the air, the river, the leaf. Art is applied to the mixture of his will with the same things, as in a house, a canal, a statue, a picture." Given the line of reasoning that I have been developing, this is an interesting observation for two reasons. First, this dichotomy is much older than I originally thought. And second, according to Emerson, the artificial must be intentional as he requires "the mixture of will". This is interesting because, if we follow Emerson, epiphenomena or side effects don't count. This makes the dichotomy a trichotomy: the natural, the artificial, and the epiphenomena.
Here is a link to the essay Nature The quote is in red in the last paragraph in the introduction.