what figure of speech is used by the landlord in stanza 6

In stanza 6, the landlord says:

"Sure, I'm an American. America never was America to me, And yet I swear this oath-- America will be!"

In this stanza, the figure of speech used by the landlord is irony. Irony is a literary device in which words are used to convey a meaning that is the opposite of their literal meaning or expectations. The landlord, despite proclaiming his American identity, expresses a deep dissatisfaction with the current state of America, suggesting that it has not lived up to its promises and ideals. The irony lies in his declaration that America "will be," implying a future transformation, while simultaneously acknowledging that it has not been so in the past.