From Isaac Leeser's Mahzor (1837), vol. 2, part 1 (Yom Kippur):
Click on image to enlarge to see the instruction in the footnote that שאו שערים is not said in Philadelphia.
"The clash of opinions honestly thought out is far better than a unanimity obtained by the enforced or voluntary suppression of the reasoning faculty." -Sir Leon Simon, The Elements of Zionism (London: Association of Young Zionists, 1934), p. 5.