Massachusetts Institute of Technology
Mit: Invention of the Week: Alexander J. Cartwright
Read about the man who invented the modern-day sport of baseball, Alexander Joy Cartwright. This article talks about the history and development of the sport and gives example the rules in other "versions" of baseball.
Other
Mr. Baseball: Alexander Cartwright Jr.
This site from Mr. Baseball has information about the man who created the modern rules of baseball, Alexander Joy Cartwright.
Wikimedia
Wikipedia: Abner Doubleday
This site from the encyclopedia Wikipedia describes the military career of Abner Doubleday and disputes the idea that he is the inventor of baseball. Links are provided for additional information on related subjects.