Why has American work ethic been seen as a key ingredient top our economic success?

Convinced that selfreliance, the work ethic, and aggressive individualism forged in the crucible of America's frontier experience had been key ingredients in the ... what would sustain such traits in a 20th-century world marked by the growth of ... industrial labor, their presence was essential to the country's rapid economic .

Explanation:

he was in office from 1929 to 1933 and served as a reform governor, promoting programs to combat the economic crisis besetting the united states at the time. in the 1932 presidential election, roosevelt defeated republican president herbert hoover in a landslide.

explanation:

the answer to your question is a. the salt plains

in 1811, he led an expedition, known as the george c. sibley expedition, to improve relations with the pawnee and kansa tribes, and also to locate the rumored jefferson's salt mountain