From UNESCO’s website:
UNESCO first adopted 21 March as World Poetry Day during its 30th General Conference in Paris in 1999, with the aim of supporting linguistic diversity through poetic expression and increasing the opportunity for endangered languages to be heard. World Poetry Day is the occasion to honour poets, revive oral traditions of poetry recitals, promote the reading, writing and teaching of poetry, foster the convergence between poetry and other arts such as theatre, dance, music and painting, and raise the visibility of poetry in the media. As poetry continues to bring people together across continents, all are invited to join in.World poetry day website
Bill Moyers interviewed Berry in 2013.