In this short, playful poem by Emily Dickinson, the speaker claims to be "nobody" and seems very proud of it. Obviously a person cannot literally be "nobody" because everybody, by definition, is somebody. In this poem the speaker is proud to declare she is not a self-promoter, someone who blows his or her own horn. This becomes evident in the second stanza when she speaks about those who qualify as "Somebody." These are the people who publicly proclaim their greatness to the world. She compares them to frogs. In the spring, bullfrogs croak out loudly in the swamps. Often people hear them, but don't see them, but those in the swamp have a view of the bullfrog's expanding chest as it croaks out its not-very-musical, repetitive call that sounds like it is saying "me-ee, me-ee, me--ee." Some people are like this--always talking about themselves, telling stories that make themselves look good, and bragging about their accomplishments. The speaker is repulsed by such self-centered showmanship and wants no part of it. She is proud that she can be who she is without needing to bellow her greatness to the "admiring bog," that is, the community she lives in.
It's tempting to associate this poem with its author and with America's other great poet of the time, Walt Whitman. Emily Dickinson was a private person who only published a few poems during her lifetime. However, she wrote hundreds of personal letters to friends and family and shared her poetry with them. Upon her death, her niece was surprised to find her dresser filled with beautiful bound fascicles of Emily's poems that she had copied out and stitched together by hand. These were published after her death. Walt Whitman, on the other hand, fancied himself as America's bard and went to great lengths to create a public image of himself. He hired professional photographers to take pictures of him, one of which shows him holding a butterfly, which was, of course, cardboard, despite his claims to the contrary. One of his best-known poems is called "Song of Myself." When Whitman's first edition of Leaves of Grass didn't sell many copies, Whitman wrote positive reviews of the book anonymously to help boost its sales. Since Dickinson and Whitman were contemporaries yet had such obvious differences in regard to self-promotion, one can wonder whether she had her fellow poet in mind when she penned this verse.