The collection consists of 890 documents, primarily letters written by Jefferson and letters written to him, arranged in chronological order. There are also notes in Jefferson's hand, pamphlets, and circulars. Jefferson kept copies of his outgoing correspondence and filed all letters alphabetically and chronologically, making them quickly accessible for later use. His filing notes are evident on most of the documents in the collection. Many of the documents dating after 15 June 1804 are polygraph copies written with the polygraph machine, a device that Jefferson acquired from Charles Willson Peale in March 1804 during his first term as president. Polygraph copies are evidenced by the end of Jefferson's use of the letterpress technique, close examination of the letter, and by the fact that in Jefferson's later years they are written on the back of old envelopes. If the document inventory does not indicate "press copy," referring to the technique of using a letterpress to make copies, or "polygraph," it has been determined that the documents are either original or may be original (some polygraph copies are difficult to distinguish between what is actually his handwriting and that of the machine). Documents in the collection, regardless of which public office Jefferson held at the time the documents were written, are a combination of personal correspondence with friends, business and personal financial transactions, official correspondence that Jefferson received by nature of his duties, or letters from strangers requesting Jefferson's assistance in various matters. Therefore, it is difficult to characterize the content of the documents by the nature of Jefferson's public offices. The combination outlined previously endures throughout the collection. The earliest document in the collection is a map dating from approximately 1773 that shows land leased from Jefferson's extensive land holdings in Albemarle County, the Shadwell quarter farm. The next document is dated 1779, from Jefferson's first year as governor of Virginia. However, the collection contains few documents from his governorship of Virginia. The bulk of the collection dates from the years of Jefferson's presidency, 1801 to 1809. The documents created during Jefferson's presidency, 1801 to 1809, include personal correspondence with friends, such as Madame de Tesse, aunt of the Marquis de Lafayette, congratulatory letters, and letters from individuals wishing to be considered for government appointments or asking for financial or official assistance. Few documents in the collection relate to important matters of state. Two letters written by Jefferson in 1806 to Reuben Lewis, Meriwether Lewis's brother, relate to the progress of the Corps of Discovery across the new Louisiana Territory. These are the only two letters referring to the Lewis and Clark expedition. Several letters dating from his presidency refer to diplomatic difficulties with Spain and Great Britain without going into detail. Many of the documents did not have dates and were dated from another source or from internal evidence. These documents are indicated by brackets around the dates: [20 July 1787]. Documents dated from other sources contain a reference to the source in parentheses at the end of the description. Often the source is an edition of The Papers of Thomas Jefferson, which is cited with the editor's name first, the title, and the volume and page numbers (e.g., Julian Boyd, ed., The Papers of Thomas Jefferson, Vol. 1, p. 100.).