The noblest monument to peace and to neighborly economic and social friendship in all the world is not a monument in bronze or stone, but the boundary which unites the United States and Canada — 3,000 miles of friendship with no barbed wire, no gun or soldier, and no passport on the whole frontier. Mutual trust made that frontier.

Franklin Delano Roosevelt (1882–1945) American lawyer, politician, statesman, US President (1933–1945)
Speech (1936-08-14), Chautauqua, New York
    (Source)

The film recording of the speech shows minor variations from the official text above:

The noblest monument to peace, the noblest monument to economic and social friendship in all the world is not a monument in bronze or stone, but the boundary which unites the United States and Canada -- 3,000 miles of friendship, with no barbed wire, no guns, no soldiers, and no passports on the whole frontier. What made it? Mutual trust.