Final answer:
The poem Composed upon Westminster Bridge was written by William Wordsworth, a poet of the Romantic Period. While the poem captures urban beauty, it retains Romantic qualities through its language and imagery.
Step-by-step explanation:
William Wordsworth is the author of the sonnet Composed upon Westminster Bridge. This poem, written during his trip to France in 1802, reflects on the serene beauty of London's cityscape in the early morning, which was a significant departure from the typical Romantic era's emphasis on natural over urban landscapes. Despite the urban subject, Wordsworth incorporates Romantic elements in the language and imagery of the poem, capturing the city in a moment of calm and beauty.
In timeline with Wordsworth's life, the composition of the sonnet was around the period when he dealt with complex personal affairs, including resolving his responsibilities with his French daughter and her mother, before marrying Mary Hutchinson. Emotional distress characterized this period, as seen in his poetry, due to various personal and political challenges he faced, including his friend Coleridge's struggles and his own opposition to Napoleon's actions.