Stirling, S.M., and Richard Foss. "Compadres"
Divergence: 1848 CE
What if: The border between the U.S. and Mexico ended up well south of the Rio Grande at the end of the Mexican-American War.
Summary: One of Mexico's greatest fighters meets Teddy Roosevelt and later joins him on the road to the White House.
Published: In Alternate Generals II (ed. Harry Turtledove), q.v.; and Ice, Iron and Gold, Night Shade 2007 (1597801151BUY).