As with every literary movement, the Romantic period came about as a renouncement against the Age of Reason.
The Age of Reason was filled with texts which told readers how to think, what to believe in, and how to live their lives. One famous work of this period was Paine's "Common Sense". One can tell from the title that Paine was letting people know that the ideas shared ion the text should be ones that everyone agreed with based upon the fact that the ideologies were common sense. The text was meant to spread the acceptance of republicanism, denounce Britain, and gain support for the Continental Army which would allow for a break from the Crown.
Romantics were not happy being told what to think. Instead, the characteristics common to Romanticism were ones which encouraged intuition and feeling, the importance of imagination, and the impact of natural elements.
Two of the Romantic poets, Dickinson and Whitman, created poems which highlighted the importance of nature while emphasizing the impact of imagination and intuition.
Dickinson's poem "Because I could not stop for Death" explicitly shows her regard for the abstract having a strong hold over her imagination. Death, personified in the poem, accompanies the speaker on a carriage ride through the countryside. An author from the Age of reason would frown upon this given it was too imaginative.
Romantics revolted against the Enlightenment's emphasis on reason and rationality and instead emphasized emotion. In revolt against the Industrial Revolution and its tendency towards mass movements, urbanization, and sameness, Romanticism instead focused on the individual and on individual experience. The movement was at its height from 1800 to 1850 and also sought to provoke strong emotions such as horror and awe in its works of art. In reaction to the industrializing forces in Europe and America, Romanticism also glorified nature and the ability of nature to produce emotions and to cultivate a sense of wonder at the sublime. Romantics sought refuge in nature as a place of contemplation and wonder away from the mass forces of the Industrial Revolution.
The Romantics also revolted against Classicism, which had been popular during the Enlightenment, and revived Medievalism, including the art and narratives of the Medieval Era. For example, the illustrations of Blake are influenced by Medievalism, as are the novels of Walter Scott such as Ivanhoe (1819), which takes place in the Middle Ages. Medievalism was seen as provoking emotion and wonder, as opposed to the Classical emphasis on reason and progress.