SOON AFTER the signing of the Declaration of Independence, John Adams, who had led the fight for it and understood well the sacrifices demanded by it, wrote a letter of exultation to his beloved wife, Abigail, back home.

“I am apt to believe it will be celebrated by succeeding generations as the great anniversary festival. It ought to be commemorated as the day of deliverance, by solemn acts of devotion to God Almighty. It ought to be solemnized with pomp and parade, with shows, games, sports, guns, bells, bonfires, and illuminations, from one end of this continent to the other, from this time forward forevermore,” he wrote.

“You will think me transported with enthusiasm, but I am not. I am well aware of the toil and blood and treasure that it will cost us to maintain this Declaration and support and defend these states. Yet, through all the gloom, I can see the rays of ravishing light and glory. I can see that the end is more than worth all the means. And that posterity will triumph in that day’s transaction . . . ”

When he wrote that, he was at risk of being seized by the British and hanged as a traitor.

The war ground on for seven more bloody years, claiming much of the treasure of the country and the lives of thousands of young men from grimy, tattered armies that looked more like crowds of homeless than official troops. While not a soldier, Adams too endured great hardship. He suffered scorn, political back-stabbings, vicious calumny in the press and the betrayal of friends — all for sticking to the noble task of trying to create a government that represented the people and protected their liberties, steering it away from the almost inevitable tendency of democracies to transmogrify into mobocracies that loot the minority to promote the corrupt and ultimately tyrannical ends of politicians.

Such a revolution as the one Adams fought had never been successful. There was no clear roadmap for Adams and the others, many of them men only in their 30s and 40s. They essentially had to make it up as they went along. But they did. We in America, and people around the world who cherish freedom, are profoundly in their debt.

Just as Adams predicted, Independence Day will be celebrated this long weekend with shows, games, sports, guns, bells, bonfires, illuminations — and prayers. We would be doing ourselves a great favor if we also paused to think about Adams, and his generation, and what kind of country they were trying to create.

A painless (and fascinating) way to get into it is through the HBO series John Adams, just out on DVD, based on the biography by David McCullough. Though seven parts long, it only skims over the extraordinary events in Adams’s life and the profound influence he had on creating our constitution that limits and balances power. But, unlike most of what you see on TV, it is thought-provoking, beautifully shot, and attempts to be true to history rather than to promote an overt agenda.

My favorite actor plays Adams: Paul Giamatti, sometimes called the patron saint of pinot noir for his role as the merlot-detesting wine connoisseur in the movie Sideways. He beautifully captures the nebbishy quality of Adams, who was short, fat, bald, vain, hot-tempered and far too honest and outspoken for his own good. Unlike Washington and Jefferson, Adams is incapable of being turned into a marble statue. And Mr. Giamatti gets better as the movie goes on, growing more creaky and cranky, as Adams realizes that the more he reads and thinks, the greater a mystery life is.

The sparkling Laura Linney (a Brown grad) is superb as Abigail, whom John described as his “ballast,” keeping the family going and running the farm on her own, while steering him in the direction of achieving his goals with her remarkable political savvy. Their 54-year marriage, sustained by deep affection and friendship, though not always happy, is the heart of the series (and the life).

The movie recreates the 18th and early 19th centuries like nothing I’ve ever seen, with the possible exception of Stanley Kubrick’s Barry Lyndon, to which it pays homage. The 18th Century was not a pretty place, and the film shows it: the filth, the disease, the stained clothes, the sweat dripping from the faces of fat men debating independence, the teeth that yellow and blacken as the characters age. A mob’s tarring and feathering of a British agent stripped naked is portrayed not as the harmless prank we sometimes imagine, but as the vicious act of burning and torture that it was. I could not bear to watch the depiction of Adams’s daughter Nabby, who died of breast cancer, undergoing a mastectomy without anesthesia.

In one of the most stunning scenes, the Adamses arrive at the half-built White House in the still largely imaginary Washington, riding up a muddy path amidst a forest of snow-dusted stumps. It looks like a post-nuclear landscape. That marvelously symbolizes the challenges John faced as president, trying to preserve freedom, in a forlorn place, in a country whose vision of itself was greater than its resources.

The film ends with a quote by John Adams from 1777: “Posterity! You will never know, how much it cost the present Generation, to preserve your Freedom! I hope you will make good use of it. If you do not, I shall repent in Heaven, that I ever took half the Pains to preserve it.”

The rest, in other words, is up to us.

Edward Achorn is The Journal’s deputy editorial-pages editor ( eachorn@projo.com).