Which is the best example of a primary source document useful in the study of history?

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.

“a committee reviews the bill and marks it up to make it more viable and to reflect interests