what is its role in popular culture?
It appeared in the 1989 American film "Dead Poets Society".
O Captain! My Captain!
The poem has additionally made an appearance in pop culture, notably in the 1989 American film "Dead Poets Society". 
o captain my captain our fearful trip is done meaning It an extended metaphor poem about the death of U.S. President Abraham Lincoln who composed it? Walt Whitman what can you tell me about its structure? It utilizes a rhyming structure and is designed for recitation; three stanzas, consisting of four seven-beat lines each; refrain at the end that changes only slightly from stanza to stanza. what response did the poem receive? The poem was Whitman's most popular during his lifetime - In early 1866, a reviewer in the Boston "Commonwealth" wrote "this displaced and slighted poet has written the most touching dirge for Abraham Lincoln of all that have appeared."
wiki:18329679
O Captain! My Captain! [SEP] In popular culture
The poem has additionally made an appearance in pop culture, notably in the 1989 American film "Dead Poets Society". John Keating (played by Robin Williams) is an English teacher at the [fictional] Welton Academy boarding school. In his first class with the students, Keating asks the students if they've heard the line "O Captain! My Captain". Seeing that no students recognize the quote, he gives a brief introduction of Whitman's poem. Following this preface, Keating says, "Now in this class, you can either call me Mr. Keating, or if you're slightly more daring, O Captain! My Captain." Keating is later fired from the school and replaced by a strict schoolmaster.