The alphabet emblems are the most famous feature of the New England Primer. Short poems as a way to teach the alphabet extends as far back to at least the sixteenth century. For example, in 1552 a tract entitled "Alphabetum primum Becardi" has a little rhyme for each letter. The Primer's rhymes do not appear to have been published anywhere before the book itself. Ford speculates that Benjamin Harris, the supposed compiler of the book, wrote the rhymes himself. He had written other verses, so it is not implausible. The rhymes were probably written after 1660; the "O" verse tells the story of Charles II and the oak: "The Royal Oak / It was the Tree / That serv’d his / Royal Majesty".
The emblems went through several iterations. The mid-eighteenth century versions are the most religious. After this point, the alphabet became more secular, as they had been in the early eighteeth century. At the end of the eighteenth century, during the American Revolution, statements celebrating the monarchy were replaced by pro-revolutionary or everyday ones.
During the First Great Awakenining, a much more evangelical alphabet was included in the Primer. In the following edition of 1762, for example, we can see the increasing emphasis on religiosity in the text (click to enlarge).