The connection I made to this poem was a person giving sympathy to a poor, helpless bird trying to escape a cruel, dark cage he has been locked away in.
This poem is organized with 3 Stanzas, each Stanza having 7 lines and an interesting rhyming of ABAABCC ABAABAA ABAABCC.
The tone of this poem is sympathetic. For example "I know why the bird beats his wing till its blood is red on the cruel bars For he must fly back to his perch and cling And a pain still throbs in the old, old scars And they pulse again with a keener sting - I know why the bird beats his wing."
In this poem, I found Personification such as "Cruel bars." and "Bird sings" plus "Springing grass." I also found a simile "The river flows like a stream of glass." Plus some alliteration here " heaven he" and "Through the." And last but not least, Hyperbole such as "I know what the caged bird feels."
I think the meaning of this poem is a Poet describing the terrible life of a poor, helpless bird, while the poet being sympathetic towards the little caged bird.