Origin of our poetry’s American, like Browning’s land from Whitman’s? (7)

I haven't cracked this one yet — but the brilliant team at Fifteensquared have:

1st letter of ( Origin of ) “ our ” + VERSE(poetry) + A(abbrev. for things American). Defn: Like England, poet Robert Browning’s homeland in relation to America, poet Walt Whitman’s homeland.