The author discusses American philosopher, psychologist, and educator John Dewey and the Laboratory School he founded at the end of the nineteenth century at the University of Chicago, where he conducted important studies of child development. The author notes the influence of Dewey's theory of (and pedagogical guidelines for) children's play, which he initially formulated between 1896 and 1900 and which subsequently influenced such play theorists as Lev S. Vygotsky and Loris Malaguzzi. However, the author asserts, the literature on play has largely neglected Dewey and contains no account of his important and influential early works about play, a gap he intends this article to fill.