Missouri

The Gateway Arch stands 630 feet tall and 630 feet wide at its base, on the Mississippi riverfront where St. Louis was founded in 1764. It marks the westward expansion of the United States, from a city that grew up as a river port.

Eero Saarinen won the national design competition in February 1948 and died in 1961, before construction began. Work ran from February 12, 1963, to October 28, 1965: a skin of stainless steel over a steel frame, two legs rising toward each other. On the last day the heat had expanded the south leg and narrowed the gap by five inches, so the crew sprayed it with water to cool it, jacked the legs apart, and set a ten-ton keystone by noon.

The picture sets the Arch against a sunset of orange, coral and yellow, its steel catching the last light above a downtown skyline with a domed building at the center. On the river in front, a white paddlewheel steamboat with a red wheel and two black stacks trails smoke, and 'MISSOURI' is set in cream capitals on a navy band at the bottom, between red rules.