In the history of the modern American civil rights movement, three iconic moments are typically cited.

May 17, 1954: The U.S. Supreme Court handed down its decision in Brown v. Board of Education of Topeka, declaring segregated — "separate but equal" — public schools unconstitutional.

August 28, 1963: Two hundred thousand Americans participated in the March on Washington and heard Martin Luther King Jr., proclaim his dream of a country in which his children will be judged by the content of their character rather than the color of their skin; 10 months later, Congress enacted the 1964 Civil Rights Act.

March 3, 1965: Civil rights marchers were assaulted by police tear gas and billy clubs on the Edmund Pettis Bridge in Selma, Alabama; five months later, President Lyndon B. Johnson signed into law the Voting Rights Act, vindicating the Selma marchers' cause.

These were noble moments, worth remembering. Yet I also believe there was a fourth iconic moment in America's journey from a land fouled by segregation to the most racially egalitarian nation on the planet. The man at the center of that fourth dramatic moment was an American legend whose accomplishments should rank as high as anyone's in the pantheon of civil rights heroes.

On April 15, 1947, the Brooklyn Dodgers opened the season against the Boston Braves at Ebbets Field. The Dodger first baseman that day was Jackie Robinson: the first African-American to play in a major league game since the infamous "color line" was drawn in the 1880s. At UCLA in 1939-41, Robinson was perhaps the greatest amateur athlete in the country, a star in track-and-field, football and basketball. After service as an Army officer in World War II, he was playing shortstop for the Kansas City Monarchs of the Negro American League when he was signed to a minor league contract by Branch Rickey, a cigar-chomping Methodist and the Dodgers' general manager. Rickey was determined to break the color line, and he deliberately chose Jack Roosevelt Robinson to do so.

And not because Jackie Robinson was a mild-mannered wallflower. But precisely because he was a warrior. A warrior with a difference, however: Rickey, an adept psychologist who believed in the essential fairness of the American people, wanted a man with the courage not to fight back against the racist slurs, beanballs and spikings that were sure to come his way — but to perform unforgettably on the field.

Which is what Jackie Robinson, the immortal No. 42, delivered. Grainy black-and-white videos today remind us of a truth the baseball world learned seventy years ago this month: there has never been anything more exciting in baseball than No. 42 stealing a base, especially home. Rather than hollering back at bigots in his rookie year, Robinson beat them with a slashing, attacking style of baseball that helped lift the Dodgers to the National League pennant and brought them within one game of a World Series victory over the lordly Yankees.

It was a performance for the ages. And it changed America.

In this entertainment-saturated 21st century, it may be hard to recall the grip baseball had on the national emotions and imagination in 1947. But as the late Columbia University cultural historian Jacques Barzun used to say, whoever wants to understand the heart and mind of America had better understand baseball. On April 14, 1947, that nation-defining pastime still embodied the nation's original sin. The next day, Jackie Robinson began to accelerate a change in America's heart and mind. That change made possible Brown v. Board of Education, the Civil Rights Act, and the Voting Rights Act.

On the sapphire jubilee of his first game in the majors, America owes No. 42 an enormous round of applause and a prayer for the repose of a noble soul.

Weigel is Distinguished Senior Fellow and William E. Simon Chair in Catholic Studies at the Ethics and Public Policy Center.