Which former American president served as a diplomat to several countries, built the Smithsonian Institution as we know it, dabbled in astrology and the arts, and returned to Congress as a champion of human rights after serving an embattled four years in the Oval Office?

If you don’t know the answer, you aren’t alone.

The storied, but often untold, career of John Quincy Adams is chronicled in Joseph Wheelan’s new historical narrative, “Mr. Adams’s Last Crusade: John Quincy Adams’s Extraordinary Post-Presidential Life in Congress.”

Wheelan stumbled upon John Quincy Adams as a subject while conducting research for a previous book, “Invading Mexico: America’s Continual Dream and the Mexican War.”

The former journalist said he was intrigued by Adams’ passionate fight against the annexation of Texas and against the continuation of American slavery, and was soon following the story of Adams’ post-presidential career.

Adams shares the experience of post-presidential careers in public service with several other commanders in chief, including William H. Taft, who was appointed to the Supreme Court in 1921, and Andrew Johnson, who was elected to the Senate just a few months before his death. But Adams’ 17-year career in the House is considered an unusual path following a presidential term.

“If you look at what ex-presidents do, generally they write their memoirs, they tend to their libraries, they catch up with their golf game and all the things they neglected while in office,” Wheelan said.

In addition to serving as a detailed and well-researched account of Adams’ career, Wheelan’s text provides a glimpse of the motivational forces that drove the Massachusetts Congressman’s lifelong devotion to public service.

As the son of one of the nation’s first presidents, Adams was groomed for a career in politics.

“From the time he was a little boy, it was ingrained in him that he should serve the public, period,” Wheelan said. “[His parents, John and Abigail Adams,] shaped every aspect of his public life.”

Growing up among the Founding Fathers shaped Adams’ ideology as well.

“He was kind of a relic of that founding generation,” Wheelan said. “He believed in the Constitution, the Bill of Rights, the Declaration of Independence — he fervently believed in these things.”

It was Adams’ commitment to the country’s founding principles that led him to take controversial stances on issues such as slavery, regardless of the political repercussions.

Adams’ early interest in the abolitionist movement stemmed from his strong support of the First Amendment, not opposition to the practice of slavery. But Adams became a full-fledged abolitionist after Southern Republicans issued a gag order to prevent Congress from hearing anti-slavery petitions. They eventually censured the Massachusetts Representative twice for his insistence that the petitions be heard.

“I think that’s kind of an accomplishment, too, for a man in his 70s to change his mind on such an important issue,” Wheelan said.

Wheelan said he hopes contemporary politicians can learn from Adams’ undying commitment to serving the public good — at any political cost.

“He considered himself a man of the whole country; he put nation over party, principles over party,” Wheelan said. “I think it can help the public discourse in Washington. We would probably get further along in solving some of the major problems that we face if more Congressmen adopted that strategy.”