That "Ring Around the Rosie" refers to the Bubonic Plague makes a great, grim tale, but, as others note, it's only one explanation.
It's not particularly compelling.
Firstly, no reference to the rhyme can be identified prior to the 1800s, long after significant European outbreaks. "Rings of roses" appear in childhood games, while a rhyme chanted in Ann S. Stephens's The Old Homestead (1840) begins with "A ring – a ring of roses / Laps full of posies," and then takes its own direction.
The first definitive printing appears in Kate Greenaway's Mother Goose or The Old Nursery Rhymes (1881):
Ring-a-ring-a-roses,
A pocket full of posies;
Hush! hush! hush! hush!
We're all tumbled down.
William Wells Newell's Games and Songs of American Children (1883) prints versions he dates, with uncertain accuracy, to the 1790s and 1840s. These versions don't sound like they're describing a plague:
Ring a ring a rosie,
A bottle full of posie,
All the girls in our town,
Ring for little Josie.
Many variations follow. Would a rhyme persist for centuries without anyone documenting it, and then suddenly begin spouting permutations?
Secondly, nobody noted the plague connection before the 1900s. Numerous sources claim that folklorists Iona and Peter Opie made it first, in The Oxford Dictionary of Nursery Rhymes (1951). Those who make the claim clearly did not read the Opies, who cite unidentified modern "would-be origin finders" who have made the "plague" claim. At best, the Opies were the first to document a claim which they themselves didn't take seriously. James Leasor's The Plague and the Fire (1961) later popularized the plague origin. Leasor wrote history, but made more money from fictional thrillers.
Granted, sometimes children's rhymes reflect something deeper. And Sometimes a cigar is just a cigar, and a nursery rhyme, just a nursery rhyme.
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