The national pastime took the familiar format that baseball fans know today, with nine players per team and nine innings per game, on this day in history, March 7, 1857.
The adoption of uniform rules marked the culmination of a national convention of baseball players held over several preceding weeks between 16 different amateur organizations on the Lower East Side of Manhattan.
The convention also secured 90 feet as the distance between bases; in earlier iterations of the game, distances were marked off by pacing with steps.
ON THIS DAY IN HISTORY, MARCH 6, 2019, ALEX TREBEK SHARES CANCER DIAGNOSIS WITH THE WORLD
The same standards of baseball remain in place today, 166 years later.
"The appearance of permanence, while everything in America seems to change every 20 years, is part of baseball's special appeal," John Thorn, the official historian of Major League Baseball, told Fox News Digital.
Thorn calls a trio of recently discovered documents from the meetings the "Magna Carta of Baseball, the Great Charter of Our Game."
In the landmark sports film "Field of Dreams," Terrence Mann, played by James Earl Jones, rhapsodized to Ray Kinsella (Kevin Costner), "The one constant through all the years, Ray, has been baseball."
"America has rolled by like an army of steamrollers. It has been erased like a blackboard, rebuilt and erased again. But baseball has marked the time."
Yet America's faith in the constancy of baseball doesn't paint a true picture of the early days of the game — or recent efforts to polish it today — say Thorn and other baseball historians.
SECRET OF AGING WELL? ONE 74-YEAR-OLD WORKS OUT REGULARLY AND ‘RETAINS A SPIRIT OF ADVENTURE'
In the mid-1800s, different clubs might play by different rules, while different cities had various versions of the game. "Town ball" in Philadelphia differed from "base ball" in New York, for example.
Baseball clubs played the game informally among themselves for several years, "for its primary objectives were exercise and good fellowship," baseball authority Eric Miklich writes on 19Cbaseball.com, his detailed compendium of the early days of the game.
If the club had 10 players that day, they would play five on five, he said.
But as recreational baseball organizations exploded in popularity, so, too, did the desire to compete against other clubs — requiring agreed-upon rules to ensure fair competition.
"The number of clubs had increased nearly ten-fold, and the emphasis was rapidly shifting toward winning, and away from mere fellowship. In this new environment, there was evidently some agitation for a rethinking of the rules," Miklich writes.
"Only when the rules underwent a fairly thorough revision in 1857 did baseball’s distinguishing dimensions — teams of nine playing nine innings on a field with 90-foot base paths — enter its list of rules."
The popular origin story of baseball is that it was invented by Abner Doubleday, later a Civil War hero, in Cooperstown, New York, in 1839, and that Alexander Cartwright and the Knickerbockers Base Ball Club of Manhattan codified the game while playing baseball at Elysian Fields in Hoboken, New Jersey.
"The Knickerbocker Club had laid down baseball’s earliest surviving rules in 1845," writes Miklich.
But the Knickerbockers were not New York's first baseball club — they were an offshoot of the earlier Gotham Club — and Cartwright's role in baseball lore is largely overblown, Miklich told Fox News Digital.
"He wrote down the rules, he literally wrote them down. But he didn't invent them," the author claims.
Cartwright actually left New York for the California Gold Rush a few years later and eventually ended up in Hawaii, Miklich said.
"He didn't have the impact on baseball that people give him credit for."
Baseball was never invented; it evolved from various sporting traditions, such as cricket and rounders, much like American football evolved from rugby and soccer.
The forgotten titan of the game is Cartwright's fellow Knickerbocker Daniel "Doc" Adams, say baseball historians.
"Considered by some to be the true ‘Father of Baseball,’ ‘Doc’ Adams was elected president of the first Base Ball Convention in 1857," Miklich writes.
"With the rules better defined and with the success of the 1857 convention, the game became increasingly popular. Subsequent conventions attracted more teams. The Civil War caused membership to decrease but helped introduce the game to southern parts of the United States. The membership of the National Association of Base Ball Players increased to more than 300 members in 1867."
Baseball turned professional with the Cincinnati Red Stockings in 1869.
The National League of professional baseball was founded with eight clubs in 1876. The American League followed in 1901.
The champions of each league competed in the first World Series in 1903.
Change has been constant throughout the history of baseball, despite its reputation for foundational solidity in American culture.
CLICK HERE TO SIGN UP FOR OUR LIFESTYLE NEWSLETTER
The height of the pitcher's mound, for example, varied widely over the years. It was set at 15 inches high in 1950, then reduced to 10 inches in 1968, after pitchers came to dominate batters.
The American League famously adopted the designated hitter rule in 1973, creating two different styles of baseball.
Major League Baseball introduced inter-league play in 1997, after nearly a century of the rival leagues competing only in the World Series.
Designated hitters were adopted by the National League as part of Major League Baseball's 2022-26 collective bargaining agreement.
Major League Baseball continues to tinker with the rules today.
Most notable among several changes fans will see in 2023: a "pitch clock" to speed up the game.
Pitchers for the first time will have 15 seconds between pitches, or 20 seconds with a man on base.
CLICK HERE TO GET THE FOX NEWS APP
Said Thorn, the official Major League Baseball historian: "Baseball appears to be unchanging, even though it is constantly evolving just as the human race is constantly evolving."