They are some of the finest baseball players who ever played in Minnesota, whose skills were as boundless as their imaginative nicknames: "Big Daddy Wags," "Rocking Chair," "Double Duty," "Rock Bottom," "Puddy Pie," and, yes, even "Babe."

Yet they never wore a major league uniform, for a single reason: They were black.

Frank White of Woodbury, who comes from generations of athletes and, in retirement, still looks like he could be intimidating at home plate, has made it his mission to tell that story. And vividly so.

An exhibit drawn from an array of materials he has assembled called "They Played for the Love of the Game: Adding to the Legacy of Minnesota Baseball" is now on display at the R.H. Stafford Library in Woodbury and will remain there through June.

The exhibit has been shown at other Twin Cities sites in the past couple of years, and may go on display next spring at the Negro Leagues Baseball Museum in Kansas City — about the same time that a book White is writing about the era is to be published.

"I think this is such an untold story," he said. "For me, I think it's one of those pieces of history I can do justice to."

White said his aim is not to focus on the pain, the enormous injustice, of generations of talented baseball players being denied their full potential because of institutionalized racism. But it is an undeniable part of the story.

"My goal is to try to tell as accurate a story as I can," he said. "It is an important piece of history for us here in Minnesota.

"We like to think that here in Minnesota, Jim Crow wasn't a part of our history, but it was. I want my kids to know this story."

White's mission is both intensely personal and part of his larger work about the future of black players in the national pastime.

White's father, Louis (better known as "Pud" — that's short for "Puddy Pie"), played for the Twin Cities Colored Giants from the 1930s to the 1950s.

Minnesota never had a professional Negro Leagues baseball team of the kind that would yield such stars as Jackie Robinson and Hank Aaron. But in the early half of the 20th century, when baseball was king in America, semipro teams in the Upper Midwest proliferated, yet leagues remained separated by the color barrier. The African-American teams had names like the St. Paul Colored Gophers (honored now by the Twins on occasional throwback uniform days), Minneapolis Keystone Colored Giants, Pipestone Black Sox and Minneapolis Browns.

White's personal connection to the teams helps him in the detective work often needed to collect and document the history of those players and teams.

Basic information like boxscores has been lost, and news stories, even in the black press, are frustratingly scarce. Much of White's information is gathered from people who, like him, have firsthand recollections or had relatives who played in the leagues. With those sources growing older, there is a sense of urgency in his work.

The exhibit celebrates the accomplishments of players most have never heard of, the great "what-might-have-beens" that fill the history of black baseball. Some of the notables who played in Minnesota who later made it to the major leagues include Willie Mays (Minneapolis Millers), Lou Brock (St. Cloud Rox), Roy Campanella (St. Paul Saints), Monte Irvin (Millers) and Hank Thompson (Millers).

If his father harbored any bitterness or anger about being denied a chance to make the major leagues solely because of his race, he never expressed it, White said. "I believe that, underneath, each of them probably had their own animosities about never getting that opportunity," White said.

Jackie Robinson's breaking of the color barrier in 1947, so vividly portrayed in the recent film "42," signaled the end of the Negro Leagues. It was a slow and painful demise, White said. Other players paid a price to integrate baseball as well.

"There's a misperception that when Jackie broke the color barrier, it opened the floodgates for black players," White said. "Teams still had quota systems — that meant players were buried in the minor leagues. In essence, it killed the Negro Leagues, so that took away even that opportunity for African-American players."

By the time Robinson retired in 1957, three teams still had not integrated. Six Minnesota-connected players were the first black players on the 18 major league teams that existed at the time, including Elijah "Pumpsie" Green for Boston in 1959.

To his other mission, White also heads the Reviving Baseball in Inner Cities (RBI) for the Twins. The program was launched by Major League Baseball in 1989 in response to flagging interest in baseball and softball by urban youth, particularly among minorities.

Jim Anderson • 651-925-5039 Twitter: @StribJAnderson