By the late 19th century, baseball was widely recognized as the national sport of the United States, and had begun to spread throughout the Pacific Rim and the Americas.
[6] Consensus once held that today's baseball is a North American development from the older game rounders, popular in Great Britain and Ireland.
It contains a rhymed description of "base-ball" and a woodcut that shows a field set-up somewhat similar to the modern game—though in a triangular rather than diamond configuration, and with posts instead of ground-level bases.
[10] According to John Thorn, official MLB historian, this version of baseball may have involved hitting the ball with a hand, making it akin to today's punchball.
[15] In 1828, William Clarke in London published the second edition of The Boy's Own Book, which included the rules of rounders and contained the first printed description in English of a bat and ball base-running game played on a diamond.
[18] Among the earliest examples to receive a detailed description—albeit five decades after the fact, in a letter from an attendee to Sporting Life magazine—took place in Beachville, Ontario, in 1838.
[19] The once widely accepted story that US Army officer[20] Abner Doubleday invented baseball in Cooperstown, New York, in 1839 has been conclusively debunked by sports historians.
[21] The Doubleday myth appeared after a dispute arose about the origins of baseball and whether it had been invented in the United States or developed as a variation of rounders.
In 1889, Mills gave a speech declaring that baseball was American, which he said was determined through "patriotism and research"; a crowd of about 300 people responding by chanting "No rounders!
[35] The game's commercial potential was developing: in 1869 the first fully professional baseball club, the Cincinnati Red Stockings, was formed and went undefeated against a schedule of semipro and amateur teams.
[49] As professional baseball became increasingly profitable, players frequently raised grievances against owners over issues of control and equitable income distribution.
During the major leagues' early decades, players on various teams occasionally attempted strikes, which routinely failed when their jobs were sufficiently threatened.
[50] Motivated by dislike for particularly stingy owner Charles Comiskey and gamblers' payoffs, real and promised, members of the Chicago White Sox conspired to throw the 1919 World Series.
[55] Compared with the present, professional baseball in the early 20th century was lower-scoring, and pitchers, including stars Walter Johnson and Christy Mathewson, were more dominant.
The "inside game", which demanded that players "scratch for runs", was played much more aggressively than it is today:[56] The so-called dead-ball era ended in the early 1920s with several changes in rule and circumstance that were advantageous to hitters.
The construction of additional seating to accommodate the rising popularity of the game often had the effect of reducing the distance to the outfield fences, making home runs more common.
[57] The rise of the legendary player Babe Ruth, the first great power hitter of the new era, helped permanently alter the nature of the game.
[58] In the late 1920s and early 1930s, St. Louis Cardinals general manager Branch Rickey invested in several minor league clubs and developed the first modern "farm system".
[68] No major league team had been located west of St. Louis until 1958, when the Brooklyn Dodgers and New York Giants relocated to Los Angeles and San Francisco, respectively.
This coincidentally helped Roger Maris break Babe Ruth's long-standing single-season home run record, one of the most celebrated marks in baseball.
[72] The players' union became bolder under the leadership of former United Steelworkers chief economist and negotiator Marvin Miller, who was elected executive director in 1966.
Significant work stoppages occurred again in 1981 and 1994, the former causing a split-season playoff format, and the latter forcing the cancellation of the World Series for the first time in 90 years.
[80] The next year, Mark McGwire and Sammy Sosa both surpassed Maris's decades-old single-season home run record, and two more expansion franchises were added.
While their identities were maintained for scheduling purposes (and the designated hitter distinction until 2022), the regulations and other functions—such as player discipline and umpire supervision—they had administered separately were consolidated under the rubric of Major League Baseball (MLB).
There had long been suspicions that the dramatic increase in power hitting was fueled in large part by the abuse of illegal steroids (as well as by the dilution of pitching talent due to expansion), but the issue only began attracting significant media attention in 2002 and there was no penalty for the use of performance-enhancing drugs before 2004.
[83][84] Even though McGwire, Sosa, and Bonds—as well as many other players, including storied pitcher Roger Clemens—have been implicated in the steroid abuse scandal, their feats and those of other sluggers had become the major leagues' defining attraction.
[85] In contrast to the professional game's resurgence in popularity after the 1994 interruption, Little League enrollment was in decline: after peaking in 1996, it dropped 1 percent a year over the following decade.
[86] With more rigorous testing and penalties for performance-enhancing drug use a possible factor, the balance between bat and ball swung markedly in 2010, which became known as the "Year of the Pitcher".
The elimination of baseball, along with softball, from the 2012 Olympic program enabled the IOC to consider adding two different sports, but none received the votes required for inclusion.
[112] Seeking reinstatement for the 2016 Summer Olympics, the IBAF proposed an abbreviated competition designed to facilitate the participation of top players, but the effort failed.