Where did baseball come from? While a good number of nice things about modern life were invented by some brilliant (or very lucky) individual, current research suggests that baseball was not one of them. Baseball, it appears to current scholars, patiently evolved over many decades.
The first known written rules for the game appeared in 1845, a product of the new Knickerbocker Base Ball Club of New York City. But the Knickerbocker Club's 14 playing rules include 10 that we now know were taken from earlier baserunning games. If we date the beginning of base ball to 1845, that beginning was a very quiet affair. For nearly a decade, nearly all games played appear to have been intramural contests, and in 1854, a total of seven games among the three existing Manhattan clubs are all that are known to have been played.
In its second decade (1855-1864), base ball grew to deserve the term "national pastime." The game was being played throughout the United States, and it was poised to emigrate to many other nations, too.
Thus, to fully understand the game, and its wide appeal, we need to account for how and why it spread so quickly and so thoroughly. This site contains about 1800 accounts of base ball's local origins the first games and the first clubs known for hundreds of localities.
Note: MLB's Committee on the Origins of Baseball examined the spread of base ball over the past year, and expects to issue a report in the coming months.