James Parton (1822-91) wrote the first studious biography of Aaron Burr, published in 1857. In it he makes these remarks on the use of contemporary evidence in the study of history.
Among the volumes which “no gentleman’s library is complete without,” and which, in most gentlemen’s libraries, slumber on the shelves with uncut leaves, are the forty ponderous octavoes, containing the works of George Washington, Thomas Jefferson, John Adams, and Alexander Hamilton. That these volumes should be so utterly neglected as they are is not creditable to the national intelligence. In the Mercantile Library of the city of New York, which counts its subscribers by thousands, the condition in which these books were found by me, two or three years ago, was as follows: the first volume of each set showed marks of having been taken out and looked through, two or three times. The second volume had evidently been handled by some one adventurous person, and about half of its leaves were cut. Beyond the second volume, no traces of the hand of man were discovered; a boundless continuity of virgin pages gave the reader a pleasing consciousness that he was the explorer of untrodden regions. Yet it is by the perusal of these works, aided by the memoirs of the time, that alone a knowledge of the country’s history, during the period in which alone it had a history, can be obtained.