In 1907, Professor James G. Needham, former head of the Department of Entomology at Cornell, offered a course in limnology at the university, the first such course in the United States.
Slightly more than one hundred years later, Nelson Hairston, Jr., the Frank H. T. Rhodes Professor of Environmental Science, Liz Brown, curator of exhibits for Mann Library, and Colleen Kearns, research support specialist in Hairston's lab, were gathering material for events and exhibits to celebrate a century of limnology at Cornell. While going through Needham's papers, held in the library's Division of Rare and Manuscript Collections, they came across an undated letter to an unknown correspondent, written in a barely readable scrawl, signed, "With my best thanks, pray believe me yours very faithfully & obliged Ch. Darwin."