Friesner, Esther M. "Such a Deal"
Divergence: 1492 CE
What if: Rejected by Ferdinand and Isabella, Columbus's voyage of discovery was instead financed by a Jewish Granadan merchant.
Summary: As Catholic Spain lays siege to Granada, Columbus's ships return from meeting the Aztecs, and they carry more than gold.
Published: In The Magazine of Fantasy and Science Fiction, January 1992; What Might Have Been? Volume 4: Alternate Americas (eds. Gregory Benford and Martin H. Greenberg), q.v.; and The Mammoth Book of Alternate Histories (eds. Ian Watson and Ian Whates), q.v.