Complex sentence: In this period, he also published his first poetry collection, "Fifty Years and Other Poems" (1917), which showed his increasing political stance and adoption of the black vernacular influences that characterize his later work.
Split into simpler sentences: In this period, he also published his first poetry collection, "Fifty Years and Other Poems" (1917). It showed his increasing politicization and adoption of the black vernacular influences that characterize his later work.