Final answer:
Emily Dickinson and Walt Whitman both began writing careers with a keen awareness of rhythmic structures. Dickinson's work reflected the calculated rhythms of hymns while Whitman embraced free verse without consistent meter or rhyme. Both contributed to new directions in American poetry.
Step-by-step explanation:
The authors who began writing careers following calculated rhythmic structures are Emily Dickinson and Walt Whitman. They both established new voices in American literature by breaking away from previously established literary traditions. Dickinson's poetry, influenced by the hymnal stanza using slant rhyme, and Whitman's utilization of free verse, revolutionized the poetic form. While they share an innovative approach to poetry, Dickinson often employed a more restrained style with rhythmic patterns akin to the songs of her era, whereas Whitman was more experimental with his rhythm, embracing a free-flowing form without consistent meter or rhyme.
Dickinson's poetry was technically complex and often followed the rhythms of nineteenth-century hymns which gave her poems a musical quality. In contrast, Whitman's poetry was groundbreaking in its abandonment of traditional meters and rhymes, opting for a verse structure dictated by the natural cadences of speech. Both poets provided refreshingly different paradigms from their contemporaries, shaping future American literary movements and expanding the scope of what poetry could encompass.