Paul Giamatti and Laura Linney, <EM>John Adams</EM> Paul Giamatti and Laura Linney, John Adams

Why isn't John Adams more famous? His face isn't on Mount Rushmore or any dollar bill. Even the popular Boston beer company passed him over in favor of his rabble-rousing cousin, Sam. Turns out the legacy of our second president — and arguably most significant Founding Father — has languished in the shadows of his predecessor, George Washington, and successor, Thomas Jefferson. But the new, seven-part HBO miniseries John Adams (premiering Sunday at 8 pm/ET, HBO), based on David McCullough's Pulitzer prize-winning biography, could change that. "To me, he was always 'the boring guy,'" says Paul Giamatti, who stars as Adams. "But I found out he wasn't boring at all."

The miniseries opens with 1770's Boston Massacre and Adams' controversial decision to serve as defense attorney for the British soldiers whose attack left five colonists dead. "It really defines his character as a man of principle," screenwriter Kirk Ellis says, "and a man who believed in the rule of law and would stake everything on that principle."

Yet Adams could be conflicted about his own ambitions. A Massachusetts farmer, lawyer and political philosopher, Adams moved between his desire to be one of "the people" and his belief that he was put here to govern them. "He wanted to be president, and yet he loathed himself for wanting that," Giamatti says. "[He thought,] 'I'm not supposed to be vain like that.' And yet he can't help but tell everybody how stupid they are. Everything was so fraught for him. He was kind of a mess."

But three key accomplishments rank him among "the pantheon of American greats," according to Ellis. "He argued the case for independence on the floor of the Continental Congress; he appointed Washington head of the army; and during one of the darkest times in the history of our revolution, he negotiated our first loan from the Dutch, without which we could not have sustained the fight."

Guiding him throughout was wife, Abigail (Laura Linney), with whom he shared a deep bond. "You can't understand him unless you understand her," McCullough says. "When he addresses a letter 'My Dearest Friend,' that's very important. It isn't just that he loves her. He likes her, he respects her mind and judgment, and he needs her for that."

The miniseries follows the couple as Abigail, an early advocate of women's rights, raises their children, farms the land and even melts the family pewter to make bullets for the war. It awed Linney. "If I met her today, I'd ask, 'How did you manage to do so much alone?'"

Attention to detail was intense during the grueling 108-day shoot, much of which took place in Colonial Williamsburg, Virginia. Costar David Morse, who plays the reserved Washington, learned that early on. After long hours of debate in the Continental Congress, Morse figured he could ease up on the general's stiff posture — until he got a tap on the shoulder. "Someone would lean in and say, 'George Washington would never relax like that,'" Morse says. Unlike the volatile Adams, "Washington was always conscious of the impression he was making."

Some of the actors were, too. In a scene, later cut, featuring Adams and his son John Quincy, Giamatti — a Yale graduate — added the line, "And by the way, where's that copy of Tacitus you purloined?" (The writings of Tacitus, an ancient Roman historian, were in Adams' library.) Ellis was impressed. "Paul is the only actor I've ever worked with who could ad-lib an 18th-century line," he says. "I remember saying to him, "Where's my copy of Tacitus?!'"

Other references are more topical, such as Adams and Jefferson's argument over a strong central government versus a weaker one — a debate still contested by politicians today. Giamatti says, "I think Adams looked at himself and said, 'Well, if everybody's like me, we've got to pen them in and control them, because people are greedy and vicious and self-serving."

To Ellis, Adams was simply more in touch. "He liked to hang around in taverns and listen to what people said — while Jefferson was up at Monticello writing wonderful democratic treatises but not connecting with anybody."

Ellis hopes viewers will feel the importance of that connection when watching John Adams. "We can't have reasoned debates anymore, but these people did. And we're just damn lucky that all these guys came along at this particular time to send us on the course that we remain on today. And it's not a completed story. We're still following through on all that groundwork they laid, and nobody knows what the destination is."

Find out more about our second president with clips in our Online Video Guide.

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