The proof No Motto Seated Dollar series is one of the most difficult to collect in all of U.S. numismatics.  From the series' inception in 1840 through 1858, the Mint did not record the number of proof coins struck each year.  It is likely that very few examples were produced, particularly when one considers that there were hardly any numismatists active in the United States during the 1840s and 1850s.  Although mintage figures increased markedly beginning in 1859, collector demand remained limited and many of the proofs struck from 1859 through 1865 were probably melted as unsold at year's end.  The onset of the Civil War in 1861 resulted in considerable chaos in the Mint, reduced the already limited number of collectors and further contributed to the rarity of proof No Motto Dollars in today's market.