The Peace Arch is a monument situated near the westernmost point of the Canada–United States border in the contiguous United States, between the communities of Blaine, Washington and Surrey, British Columbia. Construction of the 20.5-meter tall arch was headed by American lawyer Sam Hill and dedicated in September 1921. The Peace Arch comme…The Peace Arch is a monument situated near the westernmost point of the Canada–United States border in the contiguous United States, between the communities of Blaine, Washington and Surrey, British Columbia. Construction of the 20.5-meter tall arch was headed by American lawyer Sam Hill and dedicated in September 1921. The Peace Arch commemorates the signing of the Treaty of Ghent in 1814, and symbolizes a long history of peace between the two nations. The monument is built on the exact U.S.–Canada boundary, where Interstate 5 on the U.S. side of the border becomes Highway 99 on the Canadian side, in the grass median between the northbound and southbound lanes.