There are plenty of poems that you could look at in order to answer this question. Whitman is of course recognised as being one of the most famous American Romantics, and so it follows that the vast majority of his works bear this stamp of being Romantic works of art.
One of my favourite Romantic poems, however, is entitled "When I Heard the Learn'd Astronomer." This poem is Romantic because of the contrast that is created through comparing a view of the night sky and the stars and planets in it that is strictly rational and based on "charts," "diagrams" and dividing and measuring them with a view that is much more mystical and instrinsic. The poem presents the speaker as attending a lecture on the universe by the "learn'd astronomer" who is clearly an expert in his field. What is strange however is how this lecture leaves the speaker feeling ill-at-ease and rather depressed. It is only when he goes outside and looks at the night sky from his non-expert point of view that he feels better:
I wander'd off by myself,In the mystical moist night-air, and from time to time,Look'd up in perfect silence at the stars.A key element of Romanticism is the way that it depends on intuition and feelings rather than on scientific formulaes and equations. These two aspects are contrasted in this poem, and the way in which the speaker finds peace and tranquility in the night sky by himself indicates the Romantic force of this poem. i hope this helps
