Livermore, a keen and eager collector, was unable to find a copy printed earlier than 1775. Ford with other discovered material in his hands could go back to the copy in the New York Public Library, dated 1727, which remains the earliest New England Primer known to be extant. Between the years 1680 and 1830 about six and one-half million Primers were printed, of which about 1,500 are still in existence.<ref>{{cite book|url=https://books.google.com/books?id=l_dAAQAAMAAJ&pg=PA9|last1=Heartman|first1=Charles M.|title=The New England Primer Printed in America Prior to 1830: A Bibliographical Checklist|date=1834|pages=9-15}}</ref> | Livermore, a keen and eager collector, was unable to find a copy printed earlier than 1775. Ford with other discovered material in his hands could go back to the copy in the New York Public Library, dated 1727, which remains the earliest New England Primer known to be extant. Between the years 1680 and 1830 about six and one-half million Primers were printed, of which about 1,500 are still in existence.<ref>{{cite book|url=https://books.google.com/books?id=l_dAAQAAMAAJ&pg=PA9|last1=Heartman|first1=Charles M.|title=The New England Primer Printed in America Prior to 1830: A Bibliographical Checklist|date=1834|pages=9-15}}</ref> |