At the very moment that someone was leaving two bombs on the sidewalk in Boston on Monday, just a few miles away thousands of people were celebrating the life of an American hero.

At Fenway Park, every player on both teams was wearing the number 42 on his back. It is a number worn by every player in baseball one day each year to honor Jackie Robinson, who broke the color barrier to become the first black player in the modern era of the major leagues.

Monday was the baseball world’s equivalent of the Martin Luther King holiday. It has particular meaning in Boston, which was the last baseball team to integrate, in 1959.

When my wife and I could no longer watch the events unfolding on television Monday — the frightened and confused crowds, the frail runner collapsing to the ground and the blood-stained sidewalks — we went to find inspiration in the movie “42,” which chronicles the life of Jackie Robinson.

Robinson’s story helped me to remember that for every senseless act of violence and for all of the hate-filled and paranoid rantings we endure in the name of politics, there are countless angels moving among us who keep lifting the human spirit and pushing the world to a better and higher place.

They do that not through hate and vengeance but through love and hope and a sense of grace in the face of discouragement and setbacks and misfortune.

Jackie Robinson had that grace. When he joined the Brooklyn Dodgers in 1947, he was the only black man among 400 professional players. That made him a target of unspeakable hatred and cruelty.

He simply kept moving forward, stoic and even noble, inspiring a generation of black children and along the way helping his white teammates and millions of fans to learn to see talent first rather than skin color.

Robinson reminds us of something important. Great social changes are seldom the product of individual leaders who live in history books.

They are the cumulative result of hundreds and thousands who brought their talents to the game, fought back their own fears, stayed calm in the face of instigation and never stopped moving forward. Each, in their own way, broke the next barrier ahead of them, and allowed others behind them to do the same.

Transformative change happens in a chain of moments, forged one link at a time. Robinson’s chain stretched back to the slave revolt of Nat Turner, Harriet Tubman’s Underground Railroad and President Lincoln’s Emancipation Proclamation.

It continued forward through thousands of black and white leaders, ministers, athletes and artists, Rosa Park’s refusal to move, the dream of Martin Luther King and the election of Barack Obama.

As I sat in that theater, I was reminded of two individuals who were links in that chain and who inspired me as a young boy, long before I realized that they were black.

The first was my mother’s favorite singer, Nat “King” Cole. Cole’s expressive and warm voice and his unfailing good humor opened American living rooms like ours to color-blind musical appreciation.

He was the first black man to have his own national television show. When it was canceled after one year despite good ratings, when national advertisers fled under racist pressure, he said simply that “Madison Avenue is afraid of the dark.” Cole was turning on the lights.

Then there was Cassius Clay, who later became Muhammad Ali after converting to Islam.

In a time when it was the habit, if not a requirement, that black men should avert their eyes at the gaze of white people, Ali proudly and audaciously proclaimed himself “the greatest of all time.”

He virtually invented the phrase “black is beautiful.” Then he backed it all up in the ring, along the way reinventing boxing from a game of ponderous sluggers to a world of delicate footwork, speed, strategy and psychology.

At the peak of his career, Ali’s anti-war stance cost him five of his best years as an athlete, but ensured that he would leave an imprint upon the country.

Whenever I find myself worrying about where America is headed, I try to remember the thousands of points of inspiration that we all have to turn to in difficult moments. And to remember what those people endured.

The architects of our future won’t be the cowards who leave explosives on crowded sidewalks but the many people who work every day for the next breakthrough that will lift us all up, open holes in the false ceilings above us and bring more sunlight into our lives.

Alan Caron is the president of Envision Maine, which is working to promote Maine’s next economy, and a partner in the Caron & Egan Consulting Group. He can be reached at:

alancaroninmaine@gmail.com