The Romantic Era
In 1789, William Lisle Bowles (1762-1850) wrote an influential sonnet sequence, Fourteen Sonnets, a sign of brighter times ahead for the form. As rational, witty, neoclassical seventeenth century poems written in heroic couplets gave way to major works in more open forms, the sonnet was somehow adapted to accommodate the literary values of this period. In many of these works one can sense the new worth placed on intuition and spontaneity.
Second, perhaps, only to Shakespeare, William Wordsworth (1770-1850) is generally considered one of the greatest sonneteers. Writing over five hundred sonnets (mostly the early ones are still read), he ushered the form back into widespread use and also revived the sonnet sequence. Wordsworth continued the work of Milton in freeing the sonnet's subject matter from the conventional and treated the sonnet as a subjective "verse essay" in which to explore his emotions (White & Rosen).
Among the well known poets of the Romantic period, John Keats (1795-1821) and Percy Shelley (1792-1822) wrote the sonnets most commonly anthologized--"Bright Star" and "Ozymandius", respectively. Other notable poets, including Samuel Taylor Coleridge (1772-1834) and Lord Byron (1788-1824), wrote a few sonnets but did their best work in other forms.
Here, perhaps even more than elsewhere, the chronological division of sonneteers is arbitrary, with Thomas Hood chosen as the Victorian to begin the next section. Also, a few of the earlier poets here might have been more comfortable in the diverse Sonnet Central group preceding.
I highly recommend the recently published anthology A Century of Sonnets: The Romantic-Era Revival, edited by Paula Feldman and Daniel Robinson, to anyone interested in this period.