For most of us, Labor Day has come to mark the end of summer.
It's the last day the neighborhood pool stays open, and the last day of freedom for our kids before the school year begins.
It's the day when summer clothes go on to the clearance racks, and autumn sweaters and jackets take their place. Football begins, baseball hits the home stretch and enormous bags of Halloween candy make their way to the front of our supermarkets.
But this year, the 125th anniversary of Labor Day, we should remember why this day is so important.
We should take this day to celebrate those people in America who still build things. Because even in our modern times, it is the builders who keep America strong and safe.
The United States officially recognized Labor Day in 1894, at the height of the industrial revolution.
At that moment - only one generation removed from the pain and horrors of the Civil War - America had begun to take its place as a global superpower.
How did this happen so quickly? In large part because America's great American workers. Over the next century, American workers would build and manufacture like no country ever had, create worldwide industries and, most importantly, develop and implement the machinery that helped win World War II and repel the greatest threat to freedom in our history.
In our 21st century culture of ideas, services and apps, it's easy to overlook or even forget the critical importance of the men and women who make things with their hands. It is tempting to think that as technology evolves, everything can be done virtually, artificially, without the sweat, experience, ingenuity and old-fashioned elbow grease that has marked the American worker for 125 years.
As the CEO of Huntington Ingalls - where for133 years, going back even before the first Labor Day, we have made the bulk of America's military ships - I can tell you that our nation still depends on the builders.
We rely on people to construct and assemble and create and repair those tangible products that matter so much to our lives. Even more, we rely on them for our very security.
We don't often think about national security this way. We focus, rightly so, on the brave men and women of our military.
We must never stop doing that, but we should expand that focus. Speaking from a personal perspective, our 41,000 employees - from fitters and welders to nuclear engineers - take raw steel and turn it into some of the most powerful and essential machines ever made, the very aircraft carriers and submarines and ships that demonstrate America's will and might all over the world.
It is awe-inspiring to see their dedication and prowess. Their skills are invaluable. As it is with all the men and women who work with their hands, our very existence depends on the machines they build.
Every day, we see stories in the news about manufacturing workers falling behind, struggling to compete and losing hope that they can keep up with the rapid changes happening in every business.
We must step forward and support those workers. They are the lifeblood of our country.
And how can we support them? We must help them adapt, learn the new skills necessary to succeed, help them adjust to ever-changing technology.
Again, I can speak from personal experience: At Huntington Ingalls, we are currently finishing construction on the second aircraft carrier named for President John F. Kennedy.
The first USS John F. Kennedy (CV 67) was commissioned in 1968 and served for nearly 40 years before being decommissioned in 2007. It was the last non-nuclear carrier.
The new USS John F. Kennedy (CVN 79), meanwhile, will be the most advanced carrier the world has ever known.
It will be fully electric, with electromagnetic systems replacing the older steam and mechanical systems. It will have networking capabilities beyond anything previously imaginable.
To build such a marvel, we have used three-dimensional renderings, lasers, augmented reality and even a Google Maps algorithm to find optimal routes for installing electric cables.
And what is the point? We have a number of workers who have built ships during the times of both USS John F. Kennedys. We have more than 1,200 "Master Shipbuilders" who have built ships continuously for more than 40 years.
These extraordinary American workers have adapted, grown, mastered new technologies and they continue to make the carriers that will safeguard America for the next half-century. They are an inspiration to us all.
And so, this is my challenge on this 125th Labor Day: We must make a new commitment to encouraging, educating, supporting and transforming our American workers. Our very security depends on it.