As a collector of alphabet books, and sometime editor of a newsletter on the subject, I have had many opportunities to consider the history of the alphabet poem. Although alphabet poems may take a wide range of forms, most are generally divided into twenty-six parts (lines, couplets, stanze...), one for each letter.
"Alphabet Poems: A Brief History,"
3, Article 2.
Available at: http://digitalcommons.butler.edu/wordways/vol28/iss3/2