These are the more widely read works from 'The Harvard Classics'. They have ~500+ ratings on Goodreads, typically many thousands. The challenge includes works by Hawthorne, Austen, Plato, Keats, Milton, Goethe, Sophocles, Poe, George Eliot, Thoreau, Byron, Shakespeare, Emerson, Washington Irving, Anonymous and many more.
Note: Regarding individual poems, they are usually a representative popular work by writers with 10 or more specific poems listed. You can easily access all the recommended poems by following the link. Most poetry is in Books XL-XLII.