Throughout baseball history, there have been a number of groundbreaking occasions. America's pastime has undergone a number of changes throughout the years that have made the game that we love great.
Some of these groundbreaking moments had to do with changing the game was played. Others changed the way that players were able to move throughout the league.
Each of these moments has had a significant impact on the game of baseball. Groundbreaking moments like the ones that will be mentioned here have helped baseball remain popular throughout the years.
Events are listed in chronological order.
Baseball was first played in Canada in 1838 and the first game in the United States occurred in 1845 (h/t 19th Century Baseball). The game played back then had many differences from the modern game that we currently watch.
For more than 25 years, there was no professional baseball in America. Teams would just travel around and play against each other, but there was not a league.
The National Association was formed and its first game was played between the Fort Wayne Kekiongas and the Cleveland Forest Cities on May 4, 1871 (h/t RotoSheet). This is considered to be the first Major League Baseball game and Fort Wayne won by a score of 2-0.
Both of those teams would struggle that year, with Cleveland going 10-19 and Fort Wayne going 7-12, but they are forever a part of baseball history (h/t Baseball Reference).
During baseball's early years, players generally stuck with the team that they began their career with. There was no such thing as free agency and Major League teams would hold on to their talent for years. Teams could sell their players, but they were not traded for other players.
This all changed in 1886. The Baltimore Orioles and a team from Lawrence worked out a trade. Baltimore received Pat O'Connell, Dick Conway and his brother Bill Conway in exchange for two players and $1000 (h/t MLB Trade Trees).
Given how big trades and the MLB trade deadline have become, this move by the Baltimore Orioles was certainly a groundbreaking one.
In baseball's early days, the mound was 50 feet away from home plate. Pitchers certainly had an advantage from this closer distance and it should be no surprise that there were some outstanding pitching numbers in the 1800s.
Once the mound was moved back in 1893, hitters took advantage. 1894 was the highest scoring season in baseball (h/t Jonah Keri of ESPN).
Moving the mound back helped usher in an era where most of the modern baseball rules were applied (h/t Bob Diskin of ESPN). It definitely helped shape the game as we know it.
One of the biggest changes to occur in baseball was the night game. For around half a century, baseball teams would only be able to play day games. This was a huge change because having games at night meant that more people could attend them and later watch them on television.
The first night game was actually played in 1930 between teams from Des Moines, Iowa and Wichita, Kansas (h/t History). Following that game, night games began to grow in popularity with minor league teams.
On May 24, 1935 the first MLB night game was played. The Philadelphia Phillies faced off against the Cincinnati Reds at Crosley Field. Cincinnati won the game by a score of 2-1 in front of 25,000 fans (h/t History).
After Moses Fleetwood Walker played his last game with the Toledo Blue Stockings in 1884, there were no African-Americans in professional baseball for an extended period of time. There was a gentleman's agreement between MLB owners not to sign African American players (h/t Kansas State University).
This meant that baseball was missing out on some superstars. Josh Gibson dominated the Negro Leagues and could have been one of the best players ever. Cool Papa Bell wreaked havoc on the base paths in the Negro Leagues. Both of these players would eventually be enshrined in Cooperstown.
Jackie Robinson would break baseball's color barrier when he played his first game for the Brooklyn Dodgers in 1947 after being signed by Branch Rickey. Robinson quickly became a star and he is forever remember for the role he had in changing baseball history.
One of the biggest baseball rule changes that happened in the second half of the 20th century was the introduction of the designated hitter. That decision has certainly been a divisive one and there are many people that like the rule and others that hate it.
The idea of the designated hitter had been around since the early 1900s, but the MLB did not seriously consider the rule until they used designated hitters in exhibition games in the 1960s (h/t Steve Wulf of Sports Illustrated).
Athletics owner Charlie Finley was a big fan of the DH rule and he wanted to see it implemented in the American League. After an owners vote, the rule was approved for the 1973 season. Ron Blomberg became the first DH in MLB history when he came to the plate on April 6, 1973.
Prior to the 1970s, a torn ulnar collateral ligament (UCL) was a career ending injury for a baseball player. When Tommy John tore his UCL in 1974, he was willing to undergo a radical surgery to repair his UCL. Dr. Frank Jobe performed the surgery and gave John a one percent chance of returning the majors (h/t Reid Forgrave of FOX Sports).
After extensive rehab, John came back in 1976 and continued to perform at a high level, posting three 20 win seasons over the next five years.
Tommy John surgery has become a common thing for major league pitchers and this groundbreaking surgery has helped an impressive number of pitchers continue their careers after what used to be a devastating injury.
The reserve clause had been in place since baseball's early days and that rule had a significant effect in preventing the movement of players from team to team. Once a players' contract ended, team retained his rights. This meant that he could either re-sign with them or ask for a release or a trade.
Curt Flood challenged the reserve clause in 1969 after he was traded to the Philadelphia Phillies. He sued the MLB the case eventually went to the Supreme Court. Although Flood lost the case, it was a big step towards free agency (h/t History).
Andy Messersmith and Dave McNally challenged the reserve clause a few years later and an arbitrator, Peter Seitz ruled that teams did not have rights to a player for their whole career (h/t MLB Players). As a result of this, free agency was born.
The baseball postseason consisted of only division winners prior to the 1994 season. In the earlier days, when there was just one division in each league, this meant that the World Series was the only playoff baseball.
Eventually, there were two division per league and the League Championship Series was added. When the MLB decided to go to three division, they added the wild card. It was supposed to be implemented for the first team in the 1994 postseason.
Adding the wild card made baseball in September much more interesting. The recent addition of a second wild card in each league has meant that an expanded number of teams are playing meaningful baseball in the last few weeks of the season.
Five teams that have won the wild card have gone on to win the World Series since 1994.
For a sport that is steeped in tradition, adding modern technology like instant replay is a big step. Although the use of instant replay in baseball is still limited since it was implemented in 2008, it is a groundbreaking baseball advancement (h/t Barry Bloom of MLB.com).
MLB Commissioner Bud Selig has said that the MLB will be expanding instant replay to be used to check if balls were caught or trapped as well as if balls hit near the foul line were fair or foul (h/t Ian Begly of ESPN New York).
There is room for more additions as well such as determining if a runner is safe or out on a bang-bang play.