Is there danger in giving governments the power to create fiat money?

yes and no. For the most part yes as it allows the government to pick and choose what is and isn't recognized as a local currency. A good example of fiat money is gold.

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.