I think that one could argue that the opening shots of Romanticism against the Neoclassical Age are present in Lyrical Ballads. Part of this would lie in the preface, which essentially states the purpose of the Romantic movement.  The Preface argues the tenets of Romanticism, defining in stark oppositional terms to its predecessor.  Poetry as an emotional movement, written about the basic elements of society, and one that seeks to broaden the subjective experience into the universal one are critical elements to both the movement and how Romantic thinkers would come to see their work.  The Romantic Era's ideas did not deviate that much from what was featured in both the work and the Preface to it.  This helps to bring to light how important the collaboration between Wordsworth and Coleridge was in ensuring that individuals understand the movement's aims and remain true to them.  In this light, I think that a summary of Romanticism can be contained in the work.  While other thinkers like Byron, Shelley, or Keats might have taken Romanticism into their own directions, much of their work can be seen in Lyrical Ballads in terms of poetic theme, devices used, and overall timbre.