Aided by the Civil War, membership grew to almost 100 clubs by 1865 and to over 400 by 1867, including clubs from as far away as California.During the Civil War, soldiers from different parts of the United States played baseball together, leading to a more unified national version of the sport.In 1903, the British sportswriter Henry Chadwick published an article speculating that baseball derived from a British game called rounders, which Chadwick had played as a boy in England. Baseball, said Spalding, was fundamentally an American sport and began on American soil.
Writing the rules did not help the Knickerbockers in the first known competitive game between two clubs under the new rules, played at Elysian Fields in Hoboken, New Jersey on June 19, 1846.
A 2005 vintage base ball game, played by 1886 rules.
Vintage games are live contests that seek to portray the authenticity of the early game.
One of the significant rules prohibited soaking or plugging the runner; under older rules, a fielder could put a runner out by hitting the runner with the thrown ball, similarly to the common schoolyard game of kickball.
The Knickerbocker Rules required fielders to tag or force the runner, as is done today, and avoided a lot of the arguments and fistfights that resulted from the earlier practice.