Dickinson's work was never published in her lifetime but has come to be appreciated as some of the finest of American poetry. The very grounded initial image of walking a dog by the beach quickly morphs into a fantastical adventure with mermaids, pearls and personifiation of the sea itself. 

https://www.poetryfoundation.org/poems/50976/i-started-early-took-my-dog-656

Find out more about Pause for Poetry at http://airglowaudio.com/pfp