Eero Saarinen, a Finnish-American architect, participated in the competition to build the Jefferson National Expansion Memorial in St. Louis, Missouri. His design consisted of an underground visitor centre and stainless steel arch.
The construction of the Gateway Arch began in February 1963 and was completed in October 1965.The arch is the same height and length, 192 metres. Each end of the arch is 18 metres deep into the ground. This together with the materials used and the design of its structure, allow the monument to adapt to possible ground movements.
The arch is composed of equilateral sections that were built separately. These taper from the bases to the top. The stainless steel parts had to be fitted on the spot, taking extreme care as the margin of error allowed was less than half a millimetre.
Although it was not as successful as expected at the beginning, today it is one of the most visited monuments in the USA. Its interior is hollow in order to have lifts that are reminiscent of a Ferris wheel. They were designed by Dick Bowser so that visitors could go to the top and see the panoramic views of the city.