How dose whittier portray garrison and himself throughout the poem?

To William Lloyd Garrison was a poem written by John Greenleaf Whittier, who was an American Quaker poet, an advocate of the abolition of slavery in the United States, and considered a Fireside Poet. A term which referred to which a group of 19th-century American poets associated with New England, and whose poetry encompassed themes and messages of morality presented in conventional poetic forms.  

In such poem, To William Lloyd Garrison, the author portrait the prominent American abolitionist, journalist, suffragist, and social reformer named William Lloyd Garrison as like a sort of fearless hero who fights against slavery. Similarly, in these verses, the author portrays himself as a supporter of Garrison's fight.

it is the background information on the characters and setting explained at the beginning of the story. the exposition will often have information about events that happened before the story began. the exposition is often the very first part of the plot.