What agricultural advancement following the end of the american civil war changed the american farm forever?

the use of a plow
the use of steel tools
the use of horsepower
the use of a combustion engine

i do not know if this question has options, but a main impact of the federal reserve act of 1913, which created the federal reserve bank, was the international use of the u.s. dollar, which soon became the world's leading currency - particularly during world war i, since many nations around the world asked the united states for money.

i also think he is correct. i believe they came to washington to protest their rights.