Goodnight Moon
(Harper, 1947)
Written by Margaret Wise Brown
Illustrated by Clement Hurd
Over 48 million and counting

The Tale of Peter Rabbit
(Frederick Warne, 1902)
Written and illustrated by Beatrix Potter
45 million and counting

The Very Hungry Caterpillar
(World Publishing, 1969)
Written and illustrated by Eric Carle
44 Million and counting