This collection consists of two manuscripts volumes containing vocabularies from numerous Indigenous languages primarily from what is now Washington, Idaho, Oregon, British Columbia, and Alaska, as well as some from the Great Lakes and central Canada, obtained by dictation from native speakers and traders of the Hudson's Bay Company.

This item contains Jefferson's comparative vocabulary, based on his collection of vocabularies taken on printed forms; a second comparative vocabulary; and John Sibley's vocabulary of the Caddo language. This document was damaged in transit from the White House to Monticello in 1809 (see letters of Jefferson to Peter S. Du Ponceau, November 7, 1817, and April 26, 1816.)