At 8:30 on a sun splashed Sunday morning, some 40,000 runners made their way down Philadelphia's main thoroughfare.

As in years past, the annual Blue Cross Broad Street Run was a mixture of chutzpah and determination, pride and purpose. But this year, there was something else. It was tangible. It was valuable. It was real.

The starting-line scene

I saw it in the opening moments of the race, as the first set of runners sprinted beneath the train trestle at Fishers Lane, a sliver of a street where a grassy hill rises up near the northwest entrance to the Logan subway station.

There were whoops from the crowd, the click of plastic clappers, the peel of cow bells and signs bearing the names of individual participants. But as the second and third wave of runners passed through, I saw other signs as well.

There was the man who jogged in silence wearing a Boston Red Sox jersey, and the duo carrying American flags that rippled in the wind.

There was the father and son dressed in matching stars and stripes.

There was my friend Don Lafferty, who jogged with his entire family.

Then, there was Kathy Brooks, who stood on the sidewalk wearing an encouraging smile and holding a large sign that simply read, "Go Fels! We heart Boston."

I asked Brooks why she was holding the sign.

"Because of what happened at the Marathon," she said. "We're supporting. I'm supporting."

She didn't say any more than that, because she knew, just as all of us did, the significance of Sunday's activities.

A 'national statement' event

Coming so soon after the horrific bombing at the Boston Marathon, this year's Blue Cross Broad Street Run was more than a Philadelphia event. It was a national statement; one that simply said, "America will not be deterred by acts of terrorism."

This run — this statement — was our opportunity to show the world that we can be vigilant, but unafraid.

It was our chance to demonstrate that we are more than the sum of our parts. It was our time to show that despite our many differences, we are fully capable of being who we say we are: The United States of America.

As I watched large runners lumbering along the asphalt, and young, flag-draped students who ran in groups, I saw a people united in the cause of freedom. I saw America on display.

But freedom is more than exercising the right to run with abandon.

It is more than enjoying a sunny spring day without fear.

Show of force

Freedom is a responsibility, and as I watched from the sidelines, I saw that responsibility embraced, but I also saw it protected by police who were out in force.

Their presence reinforced our commitment to a single goal: upholding American freedom. We haven't always lived up to that goal, but we strive to do so every day.

Sometimes we fall short, sometimes we achieve it, but we are always reaching. That is the true meaning of being an American, and that is what terrorists will never understand.

While watching people of all ages, shapes and sizes run Broad Street with unbridled joy, I saw much more than a city on display.

I saw America, with all its quirks and commonalities.

I saw America, an open society.

I saw America, a place that is far from perfect.

I saw America, a place that is safe.

Ours is a society in which the law should not restrict the individual's freedom. It should reinforce it.

Ours is a society in which the law should not act as a shackle. It should act as a key that opens up endless possibilities.

The runners who traversed Broad Street on a sun-soaked Sunday morning were a strong representation of all our country should be.

They were people of all hues and backgrounds, united in a single purpose, and driven by a common goal. They were undaunted by fear, unmoved by terror and unaffected by hate.

For one morning on the streets of Philadelphia, they were simply people, and with every step they took, they showed all of us what is possible in America. They showed that we will not be deterred.