Mary had a little lamb - use of language
The words of the American nursery rhyme Mary had a little lamb would appeal to a small children and introduces imagery of similes (white as snow) as part of use of the English language.
The words also convey the hopeful adage that love is reciprocated!
No specific historical connection can be traced to the words of Mary had a little lamb but it can be confirmed that the song Mary had a little lamb is American as the words were written by Sarah Hale, of Boston, in 1830.
An interesting historical note about this rhyme - the words of Mary had a Little Lamb were the first ever recorded by Thomas Edison, on tin foil, on his phonograph.