Flynn, Michael F. "The Iron Shirts"
Divergence: c 10000 BCE
What if: What if prehistoric native Americans horses and mammoths had not been hunted out, but were instead used by humans as transport animals.
Summary: A meeting in 13th century Ireland is visited by red men from across the Western Sea, brought by a craft based on the designs of the Norse of two centuries earlier.
Published: Posted on Tor.com, May 4, 2011.
Published: In The Year's Best Science Fiction: Twenty-Ninth Annual Collection (ed. Gardner Dozois), St. Martin's/Griffin 2012 (1250003547BUY, 1250003555BUY).
Awards: Finalist: 2011 Sidewise Award for best short-form alternate history.
Web link: Tor.com