Baseball is always fundamentally about different aspects of American identity, and today is the anniversary of several key moments:

In 1921,

At Crosley Field, Pirates right-hander Chief Yellow Horse makes his major league debut against the Reds. The Pittsburgh hurler, a member of a North American Plains Indian tribe call the Pawnees, is believed by many baseball historians to be the first full-blooded American Indian to play in the big leagues.

Note: almost all Native American players in baseball, until the recent emergence of Jacoby Ellsbury with the Red Sox, were nicknamed Chief.

In 1947

A year before President Truman desegregated the military, Jackie Robinson debuts for the Dodgers becoming the first black player to participate in a major league game this century. In front of 25,623 Ebbets Field fans, the 28-year old first baseman is hitless in three at-bats, but scores a run in the 5-3 Opening Day victory over the Braves.

Note: the threat of African-American MEN in baseball was discursively defused by infantilizing them: Jack Robinson becomes "Jackie," Willie Mays is "the Say Hey Kid."

And perhaps most interestingly for Seattle baseball fans, in 1958

On Opening Day, the transplanted New York Giants and Brooklyn Dodgers play the first major league game on the West Coast. The Californian contest sees Ruben Gomez blanking Los Angeles and Don Drysdale at San Francisco's Seals Stadium, 8-0.

Everyone usually attributes the relocation of the Dodgers and Giants to pure greed on the part of the teams' owners, but it was also an inevitable result of the huge post-World War II demographic shift of population to the West Coast (driven at first by war industries, and then GI Bill veterans relocating). The Pacific Coast League was drawing crowds, and putting talent on the field, that was very close to making it a third major league. The AL and the NL had to prevent that from happening, and so colonization of the West by the old powers of the East was inevitable. (And the first team to move West—the first ML team to relocated in generations—wasn't the Dodgers: it was the Boston Braves, who became the Milwaukee Braves in 1951 and were the first team to draw 3 million fans, before relocating to Atlanta in 1966 and annoying America and Native Americans with that tomahawk chop chant).

But it's a great thought experiment to consider what might have happened had the PCL become the third major league. The AL and NL would have had to acknowledge the league's status and add it to the National Commission, and then you'd've had the Seattle Rainiers all along, so no heartbreak of losing the Pilots and then getting the Mariners. How might the post-season have worked? Probably the PCL pennant winner would play the NL's to see who gets the Yankees, who'd get a bye every year. . .

Bonus trivia question: name the one player to play for the Boston, Milwaukee and Atlanta Braves.