What does the St. Louis Gateway Arch commemorate?

Here is the question :

WHAT DOES THE ST. LOUIS GATEWAY ARCH COMMEMORATE?

Here is the option for the question :

Westward expansion
President Dwight D. Eisenhower
Scientific Progress
World War II

The Answer:

And, the answer for the the question is :

Westward expansion

Explanation:

[STC0019958]. The Gateway Arch in St. Louis, Missouri is the largest arch in the world, as well as the largest monument in the Western Hemisphere. It was built between 1963 and 1965 as the Jefferson National Expansion Memorial to commemorate westward expansion, honouring Thomas Jefferson’s negotiation of the Louisiana Purchase and Lewis and Clark’s discovery of the west.