Dick Allen, the former Phillies slugger who won over a generation of fans by blasting home runs that often left Connie Mack Stadium, died Monday at his home in Wampum, Pa. He was 78.

Mr. Allen played nine of his 15 major-league seasons in Philadelphia, beginning his career as the National League Rookie of the Year for the star-crossed 1964 Phillies. He hit .318 that year with 29 home runs, which frequently soared over the ballpark’s left-field roof and into North Philadelphia.

Mr. Allen had been battling cancer, but a cause of death was not announced by his family.

Mr. Allen was a seven-time All-Star and won the American League MVP Award in 1972 with the Chicago White Sox. He also played for the St. Louis Cardinals, Los Angeles Dodgers, and Oakland Athletics and finished his career in 1977 with a .292 batting average and 351 home runs.

“I’m just a name,” Mr. Allen said in 1976. “God put some talent in this body and I just use it. I don’t think of the aches and pains. I just thank God for the talent that I have.”

» READ MORE: Hall of Famer Mike Schmidt hopes Dick Allen joins him in Cooperstown

Mr. Allen was the first Black star for the Phillies, the last National League franchise to integrate. His soaring home runs were popular, but he quickly became polarizing in a city bubbling with racial tension. Mr. Allen’s rookie season coincided with riots in North Philadelphia over police brutality.

“This was a time before our collective consciousness was raised, before we really understood the historical context and acknowledged the forces of racism at work,” said Hollywood producer Mike Tollin, who grew up in Havertown and is working on a documentary about Mr. Allen. “So, the greatest Phillies player in a generation was booed unmercifully by his own fans.”

Mr. Allen found himself at odds with the sportswriters, team management, and finally the fans. In July of 1965, Allen fought during batting practice with Frank Thomas, a white teammate. Allen punched Thomas and Thomas hit Allen in the shoulder with his bat. The Phillies placed Thomas on waivers after the game. Manager Gene Mauch barred any player from talking about what happened, and soon the press and fans were picking sides.

In May of 1969, Mr. Allen missed a game in St. Louis and was fined. In June, he was suspended for missing a doubleheader at Shea Stadium because he was watching his horse run at Monmouth Park.

Mr. Allen, his time in Philadelphia running out, played the field with a batting helmet to protect himself from objects thrown from the grandstand. He communicated by writing messages like “Boo” and “Oct. 2” -- the date of the season finale -- in the dirt near first base. Mr. Allen, it was often said, was ahead of his time.

“Even now, there are certain things I will do and certain things I won’t do,” he said in 1985, three months before his 43rd birthday. “So I guess you’re right. I was kind of ahead of my time. I’ll be 28 this March, you know.”

Mr. Allen is considered to be one of the greatest players to not yet reach the Hall of Fame. There was hope that that would change this month when the Hall of Fame was scheduled to vote on his candidacy, but the coronavirus pandemic forced the Hall to postpone the in-person vote to December 2021. Mr. Allen was one vote shy when the committee last met in 2014.

Mr. Allen was baseball’s best hitter over the first decade of his career, as Allen’s 165 OPS+ from 1964 to 1973 led the majors, better than all-time greats such as Hank Aaron, Harmon Killebrew, and Willie McCovey. OPS+ is an advanced metric that combines on-base percentage and slugging percentage and normalizes it across the major leagues by accounting for external factors like ballparks.

“The homer Richie hit off me in Connie Mack Stadium that time, the story’s kind been cultivated as time goes on,” Cardinals pitcher Nelson Briles said in 1983 about a blast Allen hit off him in 1967. “I remember it came off an 0-2 changeup. He killed breaking pitches, offspeed stuff. The ball hit near the top of the flagpole. I’m glad the flagpole was there. I’m also glad they tore down the stadium. That way, I can claim it never happened. It’s all hearsay.”

From 1880 to 1990, 24 players registered a slugging percentage (total bases per at-bat) of .510 or better over at least 6,300 plate appearances. Allen is the only one not in the Hall of Fame.

Mr. Allen said in August after the Phillies retired his No. 15 that he already considered himself a Hall of Famer because he was inducted into the Negro Leagues Baseball Museum’s “Hall of Game” in 2018.

“That’s the real hall for me,” Allen said. “They are a very elite group. They’re part of the legends. And to me, the way that it’s going, it could be a little political the way [the Baseball Hall of Fame] does things, but however, it’s beyond me. I pay no attention to it.”

» READ MORE: With Phillies set to retire Dick Allen’s No. 15, former teammates want the Hall of Fame to honor him this year, too

Mr. Allen was one of nine children and two of his brothers -- Hank and Ron -- also reached the major leagues. The Allens lived in Wampum, a small town 40 miles north of Pittsburgh where Mr. Allen said racial tension did not exist. He signed with the Phillies in 1960 and spent his final minor-league season in segregated Little Rock, Ark. Mr. Allen was the team’s only Black player.

Mr. Allen, in a video played at his number-retirement ceremony, said a police car pulled behind him in Little Rock while he tried to buy a soda from a machine. The officers, Mr. Allen said, pointed their guns at the 21-year-old.

“Hell, they were trying to kill me right here,” Mr. Allen said. “In America.”

He went back to his room, called his mom, and said he wanted to go home. His mother, Era, told him that God gave him his talent and he could not quit.

“Very few days went by when somebody didn’t let the air out of his tires, break the windows of his car. We were all young then and didn’t understand,” Lee Elia, Allen’s Little Rock teammate and former Phillies manager, said in 1983. “I never knew how Richie was reacting all the time, but I do remember he was scared. But it was interesting to see how much of a fan favorite he became when he got it going. I would say that introduced Richie to the hypocritical facts of life.”

The Phillies sent a contingent led by Mike Schmidt to Mr. Allen’s farm in Perkasie in February of 1975 to lure Mr. Allen back to baseball. He had announced his retirement months earlier following a trade that sent him from the White Sox to Atlanta.

Mr. Allen, wary of how he would be treated in Philadelphia, eventually obliged. He returned to Philadelphia as a veteran presence on a rising team. Mr. Allen played two seasons with the Phillies and helped them reach the postseason for the first time in 26 years.

It seemed that any wounds left from the 1960s had been healed by time. Mr. Allen joined the team in May 1975 and received a standing ovation at Veterans Stadium when his name was announced in the starting lineup. The crowd roared again when he came to bat in the first inning. Mr. Allen, six years after being driven out of Philadelphia, returned as a hero.

“I think it was the first time,” Mr. Allen said after the game of receiving a standing ovation in Philadelphia. “Somebody said I should check the city limits to make sure I’m still in Philadelphia. You don’t know what it means to me. It’s a different atmosphere now altogether.”