Oh, soaring beauty of lasting significance. On this day in 1965, at the edge of the Mississippi, the final section was placed into St. Louis, Missouri’s Gateway Arch. A stainless-steel curve of light and resolve, the Arch opens the horizon.

Part of the Thomas Jefferson National Expansion Memorial, the monument honors the Louisiana Purchase, Lewis and Clark, and America’s westward expansion. Explorer Meriwether Lewis observed, “Nature presents to the view of the traveler vast… walls of tolerable workmanship, so perfect, that I should have thought that nature had attempted here to rival the human art of masonry.”

The Arch rivals nature’s beauty. The tallest man-made monument in the United States with a height and base width of 630 feet, its tapered catenary sweeps the sky with stainless-steel passion. Designed by Finnish-American architect Eero Saarinen (1910–1961) and selected from 172 entries, it became a universal symbol of St. Louis.

“The purpose of architecture is to shelter and enhance man’s life on earth and to fulfill his belief in the nobility of his existence,” Saarinen said. Built at a cost of more than $13 million, the engineering marvel took over two years to complete. Its 142 welded triangular sections and deep foundations were designed to withstand high winds and earthquakes.

Visitors ride internal trams to a viewing room at the apex. On a clear day, the view can extend up to thirty miles in either direction. “The only architecture which interests me is architecture as fine art,” Saarinen added. “That is what I want to pursue. I hope some of my buildings will have lasting truths.”