"The Weight of the Sunrise" is a 2013 alternate history short story by Vylar Kaftan.
It was first published in Asimov's Science Fiction in February 2013.
When Francisco Pizarro and the Conquistadors arrived in Peru, Atahualpa and his troops slaughtered them.
Centuries later, emissaries arrive from the Thirteen Colonies, seeking to trade the secret of vaccination for gold.
[2] Tangent Online considered it "mesmerizing and beautifully told", and noted its "overall tone (...) of pride and hope.