This Essay or Introduction to my Researches on the Antiquities and Monuments of North and South America, was printed in September 1838 in the first Number of the American Museum of Baltimore, a literary monthly periodical undertaken by Messrs. Brooks and Snodgrass, as a new series of the North American Quarterly Magazine. Being printed in a hurry and at a distance several material errors occured, which are now rectified, and this second edition will form thereby the Introduction to my long contemplated Work on the Ancient Monuments of this continent: to which I alluded in my work on the Ancient Nations of America published in 1836. I will add some notes or additions thereto, and may gradualy publish my original descriptions and views, plans, maps &c., of such as I have surveyed, examined and studied between 1818 and this time; comparing them with those observed by others in America or elsewhere of the same character—such works are of a national importance or interest, and ought to be patronized by the States or Learned Societies, or wealthy patriots; but if there is little prospect of their doing so, I must either delay or curtail the publication of the interesting materials collected for 20 years past.