Four years ago, I wrote about my undying love for The West Wing, and mentioned, almost in passing, that my favorite holiday is the Fourth of July, and said I’d share “more on that another time.”

It’s another time. And what better time than the 250th?

I often get asked why the Fourth is my favorite holiday. The simple answer? I 💙 history. My mom taught social studies when I was a kid. I learned to read from her textbooks. I was reading maps before chapter books.

Maps were the first thing that made me realize the whole world was out there: that millions of people had come before us, and millions would come after. That’s the thing about history that never lets go of me. It’s the dizzying idea that we’re one link in a very long chain, and the links before us were just as flawed, uncertain, and hopeful as we are.

In more recent years, you’d usually find me at Van Buren Point, New York, during the holiday week. I’m thankful that my best friend Amy and her husband, Chris, open their Lake Erie cottage to me every year. It’s a quiet respite on the shores of one of America’s greatest wonders. The traditions are simple, and I wouldn’t trade them: hot dogs at 10 a.m. in the community park (yes, in the morning — don’t question it), the kids’ bike parade, and the relaxed, quiet rhythm of lake life. Baseball on in the background, a cold beer in hand, fireworks over the water. No agenda. No production. Just America at its most unhurried.

And every July 4, without fail, three things happen. I watch Slap Shot. I watch the “Isaac and Ishmael” episode of The West Wing. I share Sam Seaborn’s take on the Revolution: “We jumped out from behind bushes while the British came down the road in their bright red jackets, but never has a war been so courteously declared. It was on parchment with calligraphy, and ‘Your Highness, we beseech you on this day in Philadelphia to bite me, if you please.'”

This year, though, I’m skipping the lake. Because if you love history, you don’t miss the semiquincentennial in the city where so much of it started. Boston, fireworks over the harbor, 250 years. Sam would understand.

The long answer of why the Fourth of July is my favorite holiday lives in the closing lines of Thomas Fleming’s 1776: Year of Illusions:

“Washington and his men endured the failures and fumblings of 1776 without abandoning their commitment to the free society they were defending. At times, this required an act of faith that defied present realities. It is a faith that Americans, no matter what their discouragement, must never abandon.”

Here’s why that passage stays with me: the founders weren’t executing a proven plan. They were running a glorified science experiment with nothing more than an idea of what could be. They were flawed. Deeply. Nobody embodies that better than my favorite founding father, Alexander Hamilton, a penniless orphan immigrant who wrote his way into the room where it happens, then nearly wrote his way back out of it. As the title of one of the songs of the hit musical puts it so perfectly, “history has its eyes on you.” And it does on us, too. The experiment didn’t end in 1776. We’re still in the middle of it, and lately it feels like the lab is on fire.

That’s what Sam’s quote gets right underneath the joke. The most audacious act of defiance in modern history was declared on parchment, with calligraphy. Ideas, written down and fought for, are the whole experiment. That’s also why The West Wing means so much to me. It’s a vision of people who still believe the experiment is worth running.

“A faith that defied present realities” isn’t naive optimism. It’s a job description. It means being civically engaged when it would be easier to check out. It means voting, showing up, and getting involved. It means speaking up for the people who can’t — or who are afraid to.

So when I celebrate the Fourth, whether it’s hot dogs at the lake or fireworks over Boston Harbor in a milestone year, I’m not celebrating a finished thing. I’m celebrating an unfinished one. An experiment that only works if each generation decides it’s worth continuing.

The men of 1776 kept faith through failure and fumbling. Two hundred and fifty years later, that’s still the assignment. And the assignment has always had the same first step: Decisions are made by those who show up.

Happy Fourth. 🎆

Now go be one of them.