Thomas Kinsella first published the allegorical journey-poem ‘Downstream’ in a collection of the same name in 1962. Since then the poem has appeared in no less than five different versions, the most recent of which was published in Kinsella’s most recent Collected Poems (2001). This article charts the development of ‘Downstream’ over those forty years of revisions, suggesting that the poem reflects Kinsella’s changing attitude towards allegorical expression, and allows us to evolve a new model for Kinsella’s career.