I have a library card for the Minute Man network (serving mostly "Metrowest" Boston area) and they have a store of downloadable eBooks that are in the public domain. I decided to educate myself on the collection by searching the--what else?--poetry selection:
Ballads of Robin Hood and Other Outlaws: http://service.overdrive.com/GUTENBERG/ebooks/minuteman/epub/28744
Five Edna St Vincent Millay books (search "Millay")
http://digital.minlib.net/128D1153-07BA-41B5-AB5F-435C6F3E794C/10/531/en/PublicDomainCollection.htm
And lots of other titles.
Ballads of Robin Hood and Other Outlaws: http://service.overdrive.com/GUTENBERG/ebooks/minuteman/epub/28744
Five Edna St Vincent Millay books (search "Millay")
http://digital.minlib.net/128D1153-07BA-41B5-AB5F-435C6F3E794C/10/531/en/PublicDomainCollection.htm
And lots of other titles.