Answer:
To display a feeling of freedom through the written part of speech.
Step-by-step explanation:
Song of myself is a part of Leaves of Grass, a book by American poet Walt Whitman, who is considered as a major figure in worldwide poetry. This book is also considered as a big contribution to a new type of poetry.
By using this type of verse, which was very new for that moment, Whitman most likely wanted to continue the tone of Song of myself, keeping the lines and their content as simple as possible (but not easy), and also, it is very likely the poet tried to show that being free also took part in his poetry, by not respecting any metric feet or rhyme patterns (which are characteristics of free verse.)