NEW YORK (AP) ― The New York Yankees honored Nelson Mandela on Wednesday during their rain-delayed celebration of the legacy of Jackie Robinson, another icon of social change.

The grandson of South Africa’s first black president, Zondwa Mandela, and Robinson’s widow, Rachel, helped unveil a plaque commemorating Mandela’s 1990 speech at the old Yankee Stadium. It hangs next to the tribute to Jackie Robinson in Monument Park beyond center field at the current ballpark.

Robinson broke the color barrier in the major leagues in 1947 with the Brooklyn Dodgers.

The ceremony was pushed back a day to Wednesday because the game between New York and the Chicago Cubs on Tuesday ― Jackie Robinson Day around baseball ― was postponed by rain.

The plaque features a portrait of Mandela and a dedication.

“Able to fill the shoes of our grandfather. That is not why we are here. It’s simply symbolic to the fact that we all make up a piece of his magnificent work. I and family, just like all of you who are here, are just a custodian of his legacy,” Zondwa Mandela said before the ceremony.

“The efforts of the Robinson family, the efforts of our grandfather, should continue to give us a sense that the efforts of today are not supposed to reflect on our experience today,” he continued, “but rather that they are for the lives to follow, the generations to come.”

Yankee captain Derek Jeter presented the Mandela family and Rachel Robinson with a replica of the plaque at home plate prior to the game.

It reads: “Nelson Mandela 1918-2013. Nobel Peace Prize winner and global leader whose timeless efforts dismantled apartheid in South Africa. As President of his country, he would use South Africa’s enthusiasm for sports as a unifying force for reconciliation. On June 21, 1990, he made a memorable visit to the original Yankee Stadium and proclaimed, “You know who I am. I am a Yankee.”

“In words and deeds, he became an inspirational leader to the world. Dedicated by New York Yankees, April 15, 2014. Presented to Mandela family from New York Yankees.”

More than a dozen notable figures, including members of the Mandela and Robinson family, South African government representatives, past and present politicians and labor leaders, Yankees owner Hal Steinbrenner, and singer and activist Harry Belafonte attended a pregame news conference.

Several of those attending were present at the Mandela speech nearly 24 years ago and recalled Mandela’s charisma that day.

“I knew that he had something in mind when he walked on the stage and was going to be presented to America and all the cameras and the world focused on him,” Belafonte said.

“And he walked out in a Yankee jacket and a Yankee cap, and his first words were: `You all know who I am. I am a Yankee.’ All of America went crazy.”

“The other hero, the other great hero, Jackie Robinson, (is) being celebrated at the same time,” Belafonte added. “So we’re getting a double whammy. Jackie Robinson and Nelson Mandela being celebrated on the same day is to me a great moment.”