Why Are the Toronto Blue Jays in the MLB’s American League?

The American League champion Toronto Blue Jays open the 2025 World Series as the underdog to the National League champion Los Angeles Dodgers.

Yes, you read that correctly; The Blue Jays from Toronto, Canada will represent the American League in this year’s World Series. baseball Historians and fanatics know that the Blue Jays have always been part of the American League since the franchise’s birth in 1977. But why they joined the New York Yankees, Boston Red Sox and others in the AL rather than the only other Canadian team, the Montreal Expos, at the time in the National League, is not well known.

The irony is not lost on me that Canada’s only MLB team is part of the American League, but it actually makes perfect sense.

And before we get started, it has nothing to do with the fact that the Expos, who left Montreal and became the Washington Nationals in 2005, were in the National League. MLB didn’t care about having two Canadian teams in the same league at the time.

Instead, it’s about the team the Blue Jays just beat in the 2025 American League Championship Series, my favorite baseball team, the Seattle Mariners.

The story begins in 1969

Let’s take a short trip back to the summer of 1969.

For this season, Major League Baseball selected two teams, the Seattle Pilots and Kansas City Royals, to expand the American League to 12 teams, along with the Yankees, Red Sox, Washington Senators, Baltimore Orioles, Cleveland Indians, Detroit Tigers, Chicago White Sox, Minnesota Twins, California Angels, and Oakland for the Powers.

In 1970, the Seattle Pilots went bankrupt, forcing the team to move to Milwaukee, where they became, and remain, the Milwaukee Brewers.

Years later, in 1977, due to a lawsuit, MLB gave Seattle another crack at the franchise, which they called the Seattle Mariners, but there was one problem. The Seattle Mariners were the AL’s 13th franchise, which could cause an imbalance in both divisions of the team. It wasn’t the biggest problem in the world, but MLB decided to add another franchise to help bring balance back to the AL.

A year ago, a Toronto ownership group tried to buy the franchise and move it from San Francisco to Toronto, but the deal fell through. However, MLB saw an opportunity in giving a team to the city of Toronto, a city with a very rich history of supporting baseball. This team became the Toronto Blue Jays.

The Blue Jays and Mariners became part of MLB

The Seattle Mariners and Toronto Blue Jays officially joined MLB and the AL in 1977, and the rest is history. The Blue Jays have won two World Series titles and are playing for a third, while the Mariners’ best chance ever to reach the World Series has slipped through their fingers thanks to the Mariners’ arch-nemesis, former Houston Astros star George Springer.

So, in short, all the Blue Jays fans who are rubbing it in the faces of Mariners fans because of the way Game 7 of the 2025 ALCS was played need to remember one important thing. Without the Seattle Mariners, there would be no Toronto Blue Jays, not in their current form anyway.