Hoover Dam, AZ (2022). Other than the 19th century railroads and the 20th century interstate highways, there is likely no construction project that is responsible for opening up the American West for development more than Hoover Dam. And, there is no other public works project anywhere that commemorates itself more as an engineering marvel and also as a work of art.
On the Arizona side of the dam, sculptor and artist Oskar J. W. Hansen created a panel of bas-reliefs to honor Native inhabitants of the West. This photo is a detail of the much larger sculpture, and the full inscription from the 1930's reads, "Since primordial times, American Indian tribes and nations lifted their hands to the great spirit from these ranges and plains. We now, with them in peace, buildeth again a nation."
(Note the almost Biblical language used here. By the 1930's, the continued development of the West was dependent upon the view that Native Americans had been subjugated and "civilized," thanks in large part to science, technology, and Christianity, and that they were now accepting and supportive of white settlers).
Hoover Dam is named after Herbert Hoover, a mining engineer who in 1929 became the first US President born west of the Mississippi River. To alleviate unemployment during the Depression, his administration forcibly deported over one million Mexican Americans, the majority of whom were birthright citizens of the United States.