To them the three-hour meeting between Rickey's grandfather and Jackie Robinson on Aug. 28, 1945, has become nothing more than a bit of trivia.
He doesn't understand why, though.
"I think it has been cheated out of all its deserved standing," Rickey said. "It's that meeting that everything good that happens in the aftermath springs out of."
What happened afterward is what Major League Baseball celebrates today. For 61 years ago on this day, Robinson broke the color barrier in baseball, an event that triggered a revolution that altered the sociopolitical landscape in America.
How monumental was the integration of baseball?
Lee Lowenfish, who collaborated with Rickey III on a new book about his grandfather, said that Rev. Martin Luther King Jr. gave Rickey a book that put the event in perspective. King wrote this inscription inside: "To Branch, who made my work that much easier."
Historians do link the integration of baseball to social change in America. The successful integration of the sport did fuel progress in education, employment and politics. All were an outgrowth of a meeting that changed baseball.
The surprising thing about that meeting was that it was the first time Rickey and Robinson had met, said Bob Kendrick, executive director of the Negro Leagues Baseball Museum. The two men were in the room with scout Clyde Sukeforth, the man Rickey had assigned to mine the Negro Leagues for talent.
"During that span of three hours, this decision was made and agreed upon," Kendrick said. "You almost can't help but believe that this thing was meant to happen. These were the two people made to carry it out, and there were no forces that were gonna stop it."
In meeting, Rickey and Robinson helped America find an answer to the question of whether blacks and whites could exist in the same workplace.
"Through courageous nonviolence, they were going to take a stand on what was right," said Rickey III, president of the Pacific Coast League. "It wasn't an act."
He said that his grandfather had been plotting since 1943 to bring a black ballplayer to the Major Leagues. But Branch Rickey didn't want to put just anybody into the racial cauldron that was wartime America, Lowenfish said. Using Sukeforth, sportswriter Wendell Smith and others to scout the Negro Leagues, Rickey combed the talent available to a Major League team that had the guts to tread these uncharted grounds.
The Negro Leagues had a mix of young and old players, and Rickey was aware of how deep its pool of talent was, Lowenfish said.
But Rickey was also mindful of the fact that he had to find a man who could endure the racial slights he'd face from teammates in the clubhouse and from opponents on the day he stepped onto the diamond.
He was looking for someone who understood the times and felt a sense of destiny.
At the time, integration was in the air; Rickey knew that. The seeds for it had been planted during the war; he knew that, too.
The breaking of baseball's color barrier, if it succeeded, might speed its growth; if it failed it might push the talk of integration into the background.
So the best talent in "black baseball" wasn't what Rickey necessarily went looking for. He needed somebody who possessed a strong mind -- somebody who was unafraid to play the role of a trailblazer.
"And who walks through the door?" Rickey III said. "Jackie."
Rickey III said that his grandfather's greatest talent was judging people. If anything, he loved the opportunity to meet somebody who he thought could rise to a new level.
In their three-hour meeting, Rickey discovered that Robinson had the trailblazer's spirit.
"Aug. 28, 1945, was a remarkable day," said Lowenfish, whose book is titled "Branch Rickey: Baseball's Ferocious Gentleman."
For Rickey asked Robinson if he could hold his temper in the face of the abuse he'd surely be forced to take. Robinson told Rickey that he could.
When Robinson pledged not to create an incident, Rickey knew he had the right man for the mission -- a mission that stands among history's most important achievements in terms of its contribution to racial progress.
"In 180 minutes, one of the most monumental events in [history] happened with a handshake and a trust factor between a white man and a black man," Kendrick said. "To me, that's just amazing."
Justice B. Hill is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.