For many Americans, the Memorial Day weekend means a backyard cookout with family and friends. Some head to the beach or to a neighborhood park.

Others, recalling the meaning of the holiday itself, visit the graves of fallen soldiers, bearing flowers and wreaths. Some salute individuals they never met, while others mourn the loss of a personal hero.

The list of possible activities could go on, but ask yourself: What do they all have in common? Simply this: It’s your decision how you mark Memorial Day. Because you are free.

And if there’s one thing that Memorial Day reminds us, it’s that our freedom didn’t come cheaply. Many Americans gave what President Abraham Lincoln called “the last full measure of devotion” so that liberty could continue to ring from, yes, sea to shining sea.

It’s all too easy, especially for those of us blessed to have grown up in this great land, to take our liberty for granted. We forget that freedom isn’t free. It must be paid for, and not just once.

Again and again, Americans have stepped forward in a moment of crisis and put their lives on the line.

They fought in the American Revolution—both in the heat of summer and in the dead of winter, when snow blanketed the ground, supplies were low, and the outlook was bleak.

Our patriots prevailed, but the struggle for freedom didn’t end there. It has played out on many other battlefields in the years since. Antietam and Gettysburg. Belleau Wood and Cantigny. Iwo Jima and the Bulge. Heartbreak Ridge and Hamburger Hill. Baghdad and Kabul.

It’s their sacrifice we mark on Memorial Day. And while we feel so much sadness for their loss, I think there is something else we should consider when we recall those who fell in battle.

It comes down, I believe, to what motivated those brave men and women to do what they did. Imagine walking towards danger and possible death when every fiber of your body is screaming at you to seek shelter. What makes you march toward the guns rather than flee from them?

A soldier, it is said, fights not because he hates who is in front of him, but because he loves who is behind him.

I think that’s what it all comes down to. Those we commemorate on Memorial Day fought for mothers and fathers. For sisters and brothers. For sons, daughters, comrades, and all others they held dear.

They fought for our liberty and land, too, because they knew America is worth fighting for.

And for the last 150 years, we have given them the honor they so richly deserve.

On May 30, 1868, future president James A. Garfield spoke at Arlington Cemetery for the first national commemoration of what was then known as Decoration Day, and his words resonate to this day:

“We do not know one promise these men made, one pledge they gave, one word they spoke; but we do know they summed up and perfected, by one supreme act, the highest virtues of men and citizens. For love of country they accepted death, and thus resolved all doubts, and made immortal their patriotism and their virtue.”

We now live in an era marked by political division and social strife. Love of country is considered old-fashioned by some. So too are patriotism and virtue.

But those who feel that way forget the liberty they enjoy to express such sentiments was won by patriots who felt very differently. And it is safeguarded today by service members who do so, too.

Those brave men and women preserve the freedom we sometimes forget to appreciate. They do it for the love of their family, friends, and community. But they also do it for their devotion to each of us and the nation of which we are all a part.

Their sacrifice and strength is what America has honored for a century and a half. And it is that which gives so much meaning to this Memorial Day.