What was Walt Whitman's greatest achievement?

Whitman is among the most influential poets in the American canon, often called the father of free verse. His work was controversial in its time, particularly his poetry collection Leaves of Grass, which was described as obscene for its overt sensuality

Explanation:

Walt Whitman, in full Walter Whitman, (born May 31, 1819, West Hills, Long Island, New York, U. S.-died March 26, 1892, Camden, New Jersey), American poet, journalist, and essayist whose verse collection Leaves of Grass, first published in 1855, is a landmark in the history of American literature.

Whitman is among the most influential poets in the American canon, often called the father of free verse. His work was controversial in its time, particularly his poetry collection Leaves of Grass, which was described as obscene for its overt sensuality.