(1) What was Romanticism? (2) Who were its major figures, and what works did they contribute to its development? (3) How did its ideas differ from those of the Enlightenment and WHY?
The above answers (1-10) are spot-on. I noticed nobody mentioned any sub-categories within Romantic literature. To me, it's helpful to distinguish two small groupings in American Romanticism:
- The Gothics, best represented by Edgar Allen Poe and Nathaniel Hawthorne, who were fascinated by the 'dark side' of human nature and the supernatural. They were Romantic in their attraction to the non-rational, but specifically focused on intriguing topics of evil, insanity, ghouls, and death.
- The Transcendentalists, represented by Ralph Waldo Emerson, Margaret Fuller, and Henry David Thoreau. (Middle names were obligatory among male Transcendentalists.) These folks believe in the perfectability of the human spirit, largely through exposure to nature. They wrote inspiring verse and prose that might seem naive to other ages.
The contrasts between these two groups help to highlight the nature of Romanticism more generally.
The two most major figures of English Romanticism (which later inspired American Romanticism) were William Wordsworth and Samuel Coleridge. It is their conversations and mutual challenge that led to Wordsworth's treatise on romanticism called Preface to Lyrical Ballads published as the preface to a volume of lyrical Romantic poems. Two representative works of this seminal collection are Wordsworth's The Ruined Cottage, in which the lives of ordinary people are simultaneously praised and mourned, and Coleridge's The Rime of the Ancient Mariner, in which Coleridge successfully tested his theory of representing spiritualism by writing a literal story superimposed over a symbolic spiritualistic one.
Romanticism in some ways was a reaction to the Industrial Revolution with its advancements in science. There was an emphasis upon feeling, intuition, emotions, friendships--all the things that really make people human, not mechanical.
In response to your third question, it is important to remember that Romanticism emerged in many ways as a reaction to the extreme position of rationalism. Rationalism distrusted emotion and intuition, whereas Romanticism praised it and saw these as valid ways to make decisions and approach thinking about topics. Rationalism saw nature as something to be studied and dissected in order to search for scientific truth, whereas Romanticism simply saw nature as something to be marvelled in and wondered at.
Romanticism was in many ways a reaction to the Enlightenment, especially, as others have said, the more coldly rational elements of it. Where the Enlightenment tended to emphasize universals (rights, natural laws, etc) the Romantics emphasized historicism, focusing on the deeper organic origins of social institutions. It's true that many Romantics were what we might call "progressive," especially inasmuch as they celebrated liberal nationalism, but many were quite conservative, even reactionary, believing that mankind should return to an imagined past. It should also be noted that there was a fine line between the Romantics and Enlightenment thinkers, especially late in the eighteenth century. Rousseau, who we identify with the French Enlightenment, really espoused many ideas that we associate with the Romantics.
These previous answers are about literature and ideas and such, but Romanticism and the Enlightenment had impacts on the political realm as well. For example, Romanticism leads to such things as nationalism. It was Romanticism, rather than logic, that encouraged countries like Italy to try to unify. Romanticism, in extreme ways, can even be linked to Nazism with its emphasis on feelings and emotions rather than reason.
Romanticism is different from the Enlightenment in that the Enlightenment focused on reason and logical, while the Romantics focused on the power of imagination and intuition. Romanticism is associated with a love of nature,the natural world and the natural state of human beings. There was a great appreciation for youth, freedom and emotionality.
Romanticism in English literature is often associated especially with William Blake, William Wordsworth, Samuel Taylor Coleridge, Percy Bysshe Shelley, and John Keats.
The romantics tended to appreciate the beauty of nature; they often thought of themselves as spokesmen for common people (this is especially true of Wordsworth); they were often interested in anything lofty of "sublime"; they did not focus much of their attention on the Christian God or Christian religion as traditionally conceived; their politics tended to be "progressive" rather than conservative (at least in their youths); and they sought to break with the artificiality they associated with the poetry of the 18th century.
Some of the more important Romantic authors were Lord Byron, Ralph Waldo Emerson, Victor Hugo, Washington Irving, John Keats, Edgar Allan Poe, and Henry David Thoreau.
Composers during the period included Ludwig Beethoven, Frederic Chopin, Franz Liszt, Niccolo Paganini, and Richard Wagner.
The period of Romanticism varies on which expert you depend upon for dates. The one consensus is that Romantic works were most popular between 1800 and 1860. The authors of the time upheld the importance of intuition over reason, highlighted the power of imagination, and looked at nature as being a "being" one could find power in.