The second president was honest, passionate and far plainer in intention than Washington and Jefferson.

Of all the Founding Fathers, John Adams, who died July 4, 1826, impresses me most. He was the literal father of many, including another future president, and took great interest in shaping his children’s character. And he was the metaphorical father of a nation whose character he likewise tried to shape, often against fierce resistance.

No man was more honest, more passionate, better read or more prepared for the public offices he filled. At the same time, no man was more vilified and scoffed at. There were obvious reasons for this seeming contradiction. Adams expressed himself without moderation and was enormously thin-skinned. He couldn’t see that the men he dealt with—even those as august and admirable as George Washington and Thomas Jefferson (who died the same day as Adams)—weren’t as plain in intention as he was. He was deeply invested in doing right, even when impolitic to do so.

Men like Adams are rare in public life today. I say this because no one I know—not my children, my children’s friends or my friends’ children, all well-educated, intelligent, and honest people—has considered public office as a vocation. Where are our Adamses? Where are our brilliant public servants, fueled by intemperate idealism?

I was struck by the absence of such people in my circle after reading about Adams in Gordon Wood’s 2017 book “Friends Divided.” Adams comes off better in character than Jefferson, the man I was taught to admire above all others in grade school in the 1960s. This may be the root of the problem. We were taught Washington and Jefferson were paragons, then discovered they were human. When you teach people to worship idols, they will smash them when they are revealed to be imperfect. When you teach people to revere human beings, they will accept their failings more readily.

Adams was flawed. As vice president, he was presumed to be a monarchist because he favored a strong president and spent inordinate time arguing on behalf of a regal appellation for Washington (at one point he favored “Your Most Benign Highness”). Such quirkiness wasn’t unusual for him, though it almost always connected to some legitimate concern—in this case, his fear that, without a strong executive, the new government would dissolve into factionalism.

“Integrity,” Adams wrote to his son Thomas when under siege for unpopular policies during his vice presidency, “should be preserved in all events, as essential to [a young man’s] happiness, through every stage of his existence. His first maxim then should be to place his honor out of reach of all men. In order to do this he must make it a rule never to become dependent on public employments for subsistence.”

In a later letter to his grandson John Smith, Adams wrote in a similar vein: “Have you considered the meaning of that word ‘worthy’? Weigh it well. . . . I had rather you should be worthy makers of brooms and baskets than unworthy presidents of the United States procured by intrigue, factious slander and corruption.”

Reading about Adams, one understands how hard it is to serve with integrity. It often means taking principled stands, even if they go against one’s political interests. It may mean looking like a crank, and cranks don’t tend to get elected, let alone re-elected. Adams lost a second term as president to Jefferson, who knew how to maintain a pristine public image while machinating behind the scenes to achieve what he wanted. Adams was never able to do that.

Even now, despite the effort of some historians, Adams remains a marginal Founding Father. History prefers a polished image to a tarnished one. Yet without Adams, we might not have had a Constitution, a strong Navy, the financial aid of the Dutch during the American Revolution, or peace with France during their revolution. These achievements required integrity in the face of staunch opposition, and without them our young nation may never have survived.

Ms. Cohen is a dean and English professor at Drexel University.