I saw a live oak tree in Louisiana. What did the author praise about the oak tree?

In Louisiana, I saw an oak tree growing, and his poetry collection Leaves of Grass was included in 1855. "Leaves of Grass" in the title of poetry collection symbolizes all ordinary people and things. Freedom is a major feature of Leaves of Grass. Whitman advocates describing the laws of the universe and its creativity and richness, expressing his thoughts and feelings, and avoiding traditional poetry. Such as rhyme, meter, etc. He takes English as a completely unprocessed raw material and casts it into a new form of poetry, so his poems are very close to spoken poems and prose poems. Reminds me of myself, reminds me of men's love and so on. More importantly, the repetition of the word "I can't" reflects the poet's admiration. This tall and strange living oak tree is a symbol of loneliness and melancholy produced by the poet in his long journey of pursuing his ideal. Facing the loneliness in development, the optimistic "oak spirit" is the author's ideal. "I like this poem because of my deep affection for trees. When I face every sad parting, I always think, I wish I were a tree. In this way, the "tree" around me will never leave me and stay at the origin of time forever. I'm not sad. But I never thought that even a tree could be lonely all my life. I also began to ask myself, if I were the tree in the poem that grew alone in Louisiana, could I grow up as positively and optimistically as it did? Whitman knows he can't do it, but I wish I could. After all, life is only once. "