PHILADELPHIA -- Dick Allen's No. 15 was retired by the Philadelphia Phillies in a ceremony Thursday, a long overdue honor for one of the franchise's greatest players who fought against racism during a tumultuous period with the team in the 1960s.

Allen, 78, thanked Phillies managing partner John Middleton, who broke from the team's longstanding "unwritten" policy of retiring only the number of players who are in the Hall of Fame.

"I thank the city of Philadelphia. Even though it was rough, I've made some friends along the way," Allen said.

Allen took to Twitter to thank the Phillies after the ceremony.

A day of goosebumps... Thanks @Phillies ! pic.twitter.com/59KMqWxEsB

— Dick Allen (@DickAllen_15) September 3, 2020

Mike Schmidt, a Hall of Fame third baseman who helped lure Allen out of retirement to return to Philadelphia for a second stint with the team in 1975, called him "an amazing mentor" who was wrongly labeled a "bad teammate" and "troublemaker."

"Dick was a sensitive Black man who refused to be treated as a second-class citizen," Schmidt said in a speech.

Schmidt then unfurled a red banner revealing the No. 15 hanging on a brick wall behind the left-field stands at Citizens Bank Park, before the Phillies hosted Washington.

"He played in front of home fans that were products of that racist era [with] racist teammates and different rules for whites and Blacks. Fans threw stuff at him and thus Dick wore a batting helmet throughout the whole game. They yelled degrading racial slurs. They dumped trash in his front yard at his home. In general, he was tormented and it came from all directions. And Dick rebelled."

Schmidt pointed out Allen didn't have a negative reputation playing for the St. Louis Cardinals, Los Angeles Dodgers or Chicago White Sox.

"My friends, these [negative] labels have kept Dick Allen out of the Hall of Fame," Schmidt said. "Imagine what Dick could've accomplished as a player in another era, on another team, left alone to hone his skills, to be confident, to come to the ballpark every day and just play baseball."

Middleton choked up talking about Allen, recalling how he spent summers as a kid listening to Phillies games on a transistor radio at the Jersey shore. Allen was his favorite player.

"One of my strongest memories is a group of white suburban 8-, 9-, 10-year-old kids playing pickup ball and fantasizing we're Dick Allen," Middleton said. "For us, it had nothing to do with race. We just saw talent, extraordinary talent, more talent than we've ever seen in any baseball player in Philadelphia. We wanted to be just like Dick."

Before the ceremony, the Phillies tweeted a video with highlights of Allen's days with the team, along with a clip of Willie Mays saying he considers Allen a Hall of Famer.

"He could hit a ball farther than anybody that I've seen."@DickAllen_15 could do it all and then some. pic.twitter.com/RFz1nCYvub

— Philadelphia Phillies (@Phillies) September 3, 2020

Middleton made clear the Phillies retired Allen's number solely on his production as a player. But he also called the abuse Allen received "horrific" and pointed out his accomplishments are even greater considering the racism he endured.

Allen was a seven-time All-Star, 1964 National League Rookie of the Year and 1972 American League MVP. He batted .292 with 351 homers, 1,119 RBIs and a .912 OPS in 15 seasons. Allen played first base, third base and left field.

Allen had the fifth-most home runs (319) over an 11-year span (1964-74) behind four Hall of Famers: Hank Aaron (391), Harmon Killebrew (336), Willie Stargell (335) and Willie McCovey (327). His .940 OPS during that time was second to Aaron's .941.

Allen wasn't elected into the Hall of Fame by the Baseball Writers Association of America and he fell one vote short in Golden Era Committee voting in 2014. The Golden Days Committee and the Early Days Committee will not vote this year because of COVID-19 and instead will meet during the winter of 2021.

Allen joins Schmidt (20) and Hall of Famers Richie Ashburn (1), Jim Bunning (14), Steve Carlton (32), Roy Halladay (34) and Robin Roberts (36) as the only Phillies to have their numbers retired. Grover Cleveland Alexander and Chuck Klein are recognized with uniform insignias from their eras in place of retired numbers.

The ceremony for Allen was held on the left-field plaza. Several of Allen's former teammates and family members were there, wearing masks and sitting several feet apart. The Phillies also unveiled a statue of Allen. The team plans to honor him again next season with fans in attendance.

The Associated Press contributed to this report.