Octavius Catto’s impact was mostly unknown here at the National Baseball Hall of Fame and Museum, amid the sport’s heroic feats of lore and legend, like Joe DiMaggio’s 56-game hit streak, Ted Williams’s .406 batting average and Hank Aaron’s 715th home run to break Babe Ruth’s record.

Catto, born a free Black man, turned to baseball in the shadows of the Civil War. He was a founder of Philadelphia’s all-Black Pythian Base Ball Club, which included Frederick Douglass’s son, Charles. (They lost their first game, 70-15, but improved quickly.) The Pythians applied for and were denied entry into Pennsylvania’s association of amateur baseball and the National Association of Base Ball Players.

The story of Catto, who was also a civil rights activist before his 1871 assassination, is among many that the museum is showcasing in its new exhibit “The Souls of the Game: Voices of Black Baseball.”

“It has been documented that we’ve been playing baseball going back to the period of being enslaved,” said Bob Kendrick, the president of the Negro Leagues Baseball Museum in Kansas City, Mo., and a member of the exhibit’s advisory committee. “Baseball has always been an important part of the African American experience in this country. It’s just the fact that it wasn’t documented in the pages of American history books.”

The exhibit is opening at a time when the percentage of American-born Black players in Major League Baseball is historically low. About 40 percent of major league baseball players last season were players of color, according to a report by the Institute for Diversity and Ethics in Sport, but only about 6 percent identified as either Black or African American, the lowest since tracking started in 1991. The 2022 World Series, between the Philadelphia Phillies and Houston Astros, featured no American-born Black players for the first time in 72 years.

“It continues the conversation, which is great,” Curtis Granderson, a three-time All-Star, said of the exhibit. “And that’s what you want to have. You want to have the conversation go from one generation to the next.”

In recent years, baseball has sought to rectify previous omissions and oversights related to its history. None is more momentous than the recent incorporation of statistics from several different Negro leagues into official Major League Baseball statistics, where, for example, Josh Gibson replaces Ty Cobb for highest batting average of all time. The Hall of Fame, which is not funded by Major League Baseball, also acknowledged in recent years that the legacies of enshrinees like Kenesaw Mountain Landis and Cap Anson included maintaining the color barrier that remained until 1947.

One player the Hall of Fame recruited for its recent advisory committee was Dave Stewart, a standout starting pitcher and World Series most valuable player with the Oakland A’s, who discussed the full spectrum of his experiences to help inform the exhibition. At the start of his career, he suffered isolation as the lone Black player on a team while busing through tiny minor league towns. Once, he said, a racist tried to run him over in a parking lot in Mississippi. But he was eventually able to meet heroes from previous generations, like Bob Gibson, Roy Campanella and Don Newcombe, and found camaraderie.

“We talked about those experiences and what it felt like to be in that situation and how I was treated or how we were treated at that time,” Stewart said. “We talked about style of play. You look at guys like Rickey Henderson and Reggie Jackson, and the style and brand of play and what they did. Were they more acceptable or less acceptable because it was Rickey Henderson doing it versus if Cal Ripken would’ve done something like that?”

As part of the exhibit’s opening, there was an exhibition game featuring more than two dozen former Black big leaguers like Granderson, Matt Kemp and Prince Fielder.

“The reason I said yes was to get a chance to be with all those guys again,” said Granderson, who played in the majors from 2004 to 2019. “It’s the first time I’d be around so many Black ballplayers that I played against, played with, watched growing up.”

It was a reminder that even recently, Black representation on big-league diamonds was more common. Among the items in the new exhibit’s section on the modern era is a T-shirt worn by Mookie Betts at the 2022 All-Star game emblazoned with “We need more Black people at the stadium.”

TOM SHIEBER, THE HALL OF FAME’S SENIOR CURATOR, read from “De Witt’s Base-Ball Guide of 1868” during a recent tour of the exhibit. The document noted that the rejection of Octavius Catto’s team, the Pythians, from the National Association of Base Ball Players was based on the rationale that “if colored clubs were admitted, there would be in all probability, some division of feeling, whereas, by excluding them no injury could result to anybody.”

“It’s like, ‘What?’” Shieber asked. “It’s so weird to connect the dots that way, but they did. One thing we tell here is the color line isn’t drawn just with that moment or another. It gets heavier and bolder and bolder and stronger with all sorts of things going on.”

The new exhibit explores Jackie Robinson’s life beyond breaking that barrier, along with other, lesser-known thresholds. One item on display is the championship ring that a 19-year-old Hank Aaron received when he integrated the South Atlantic League in 1953.

Robinson’s story is universally celebrated as the tale of triumph and preservation that it is. But reintegration, as Shieber likes to call it, coincided with the collapse of the Negro leagues. The exhibit does not shy away from exploring those ramifications.

“It is absolutely a bittersweet kind of story,” Kendrick said. “Those owners and the older players in the Negro leagues essentially took one for the team. It reminds us that there is always a cost for what is deemed progress. And Black economy paid a dear cost for this progress.”

After reintegration, executives of Major League Baseball established an unwritten quota system limiting the number of Black players on rosters, Shieber said.

“This resulted in lopsided trades,” he added. “That’s not just a one-on-one trade. That’s a, ‘We’ve got enough Black players trade.’”

Near the exhibit’s end Shieber pointed out the locker once used by Willie Mays that Barry Bonds took over as a San Francisco Giants player.

One of Stewart’s cherished early memories was meeting Mays, his favorite player, as a 5-year-old. But Stewart could also look up to Gibson, Aaron, Frank Robinson and a host of other Black stars.

Today, he said, children probably emulate Betts. He struggled to name another current American-born Black star.

Under the surface, numbers are improving. The league has established several programs to encourage, identify and nurture young Black players. An increasing number of Black players have been among the top draft picks in recent years — 12 of the first 100 three years ago, 13 of the top 100 in 2022, and 10 of the top 50 in last year’s draft.

“We are going to have to be patient, though, and as a society, we aren’t very patient,” Kendrick said. “This trend didn’t happen overnight. The solution isn’t going to occur overnight either.”

Telling stories like those of Catto, from as far back as 150 years ago, will help those efforts, Kendrick believes. “It will,” he said, “be an awakening.”