He invented the number of bases,size and shape of the field,and all of the postions on the field.
Alexander played on a team called the New York,Knickerbockers with one more important person who also played a big role in the creation of Baseball,Abner Doubleday.
Alexander was born on April 17,1820 in New York City,NY and later died on July 12,1892 in Honolulu,HI.