The quote below is from an 1847 speech by George Perkins Marsh (1801-82), a native of Woodstock, Vt., to the Agricultural Society of Rutland County, Vermont. Marsh, a distinguished philologist, diplomat and naturalist, was the first modern thinker to theorize that man's activities influence climate (but never mentioning carbon dioxide). Some historians have labeled him the first American environmentalist.

"Man cannot at his pleasure command the rain and the sunshine, the wind and frost and snow, yet it is certain that climate itself has in many instances been gradually changed and ameliorated or deteriorated by human action. The draining of swamps and the clearing of forests perceptibly effect the evaporation from the earth, and of course the mean quantity of moisture suspended in the air. The same causes modify the electrical condition of the atmosphere and the power of the surface to reflect, absorb and radiate the rays of the sun, and consequently influence the distribution of light and heat, and the force and direction of the winds. Within narrow limits too, domestic fires and artificial structures create and diffuse increased warmth, to an extent that may effect vegetation. The mean temperature of London is a degree or two higher than that of the surrounding country, and Pallas believed, that the climate of even so thinly a peopled country as Russia was sensibly modified by similar causes."

Marsh is memorialized in, among other places, the Marsh-Billings-Rockefeller National Historical Park, in Woodstock. The park preserves the site where Frederick Billings established a managed forest and a progressive dairy farm. The name honors him and the other past owners of the property: George Perkins Marsh, Mary Montagu Billings French, Laurance Rockefeller and Mary French Rockefeller.