The Europeans introduced many things to the New World. Which had the most devastating impact on Native Americans?

Smallpox

Explanation: The introduction of smallpox significant damaged the native population.

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.

this question makes no sense dude