How did Americans find ideas for new technology

there were two technological innovations that profoundly changed daily life in the 19th century: steam power and electricity. The railroad helped expand the U.S.. The telegraph, the telephone, and the typewriter brought people together that were far away. ... America began producing more steel than England.

Explanation:

the great wall of china worked as a defense for the feudal states of the zhou dynasty to the north. during the warring states period more walls were put up to defend the borders of the different kingdoms. it was semi successful because despite the wall, the mongols eventually conquered china also the great wall provided protection to the economic development and cultural progress, safeguarded the trading routes such as the silk road, and secured transmission of information and transportation. @jayxboof

i am pretty sure it is a