What invention from the 2nd industrial revolution had the most impact on american life? why?

it refers to race, i am pretty sure this was a popular term in nazi germany or something.

richard milhous nixon (january 9, 1913 – april 22, 1994) was the 37th president of the united states, serving from 1969 to 1974, when he became the only president to resign (quit). he is also known for corruption and the watergate scandal which resulted in the public losing trust in him and his resignation.