The Lion & the Mouse

US-only true first: Little, Brown Books for Young Readers, New York, September 2009 (ISBN 9780316013567) — the census claim is correct. The first British edition followed from Walker Books, London, in 2010, retitled 'The Lion and the Mouse' (ISBN 9781406332049), and is a year later; it is not a precedence contender. Note the title styling: the US first uses an ampersand, the Walker issue spells out 'and'. Later Caldecott-badged US printings are the same edition, not a separate one.