HEALTH CARE CONTINUES TO COME UP IN THE CONTENTIOUS 2016 PRESIDENTIAL ELECTION. The next man or woman who takes the office will have to face runaway prices for prescription drugs and a Congress that wants to dismantle the Affordable Care Act. But as health crises go, is this the worst it can get for a president?

Not by a long shot. Four historians weigh in on the presidents who faced disease outbreaks, civil war, and the probing and unsanitized fingers of well-meaning physicians.

Thomas Jefferson (1801–1809)

If the American Revolution once defined an era, smallpox defined life in the early American republic. The epidemic claimed five times as many lives as the war did. George Washington ordered the immunization of the Continental Army using variolation, the dangerous practice of purposely infecting a person with a mild case of smallpox to prevent serious infection later.

But historian Jeanne Abrams, author of Revolutionary Medicine: The Founding Fathers and Mothers in Sickness and in Health, casts her vote for Thomas Jefferson, not Washington, because of Jefferson’s unwavering support of the Jenner vaccination. Edward Jenner had recently created the world’s first vaccine by showing that an inoculation with cowpox, a virus closely related to smallpox, offered immunity to the disease with few ill effects. Benjamin Waterhouse at Harvard had used the Jenner vaccine in 1800, just four years after it was discovered, and persuaded Jefferson to create the world’s first national vaccination program. Jefferson made the smallpox vaccine available to everyone, regardless of whether they could afford it.

He favored compulsory vaccination, a surprising footnote for a founding father known for standing against government interference. But Jefferson decided that public health needs came first. “Smallpox didn’t just devastate families,” Abrams says, “it played havoc with commerce and nation building.”

Abraham Lincoln (1861–1865)

While Abraham Lincoln fought for racial equality and national unification, medicine was never one of his causes. In fact, seven years before he became president, Lincoln prepared a charter for a Chicago college for homeopathy, a practice that the American Medical Association regarded as cult-like. As president, he did little to fund medical research. But he won the Civil War, and did so in no small part because of his support of the U.S. Sanitary Commission.

A private relief agency, akin to the modern Red Cross, the Sanitary Commission coordinated thousands of civilian volunteers who vowed to do what the government would not: improve the living conditions in the army. In 1862, the commission pressured Lincoln to appoint young William Hammond as surgeon general of the army, over the objections of his secretary of war. Lincoln complied, and Hammond transformed the sleepy post. He standardized medications and hospital ventilation, and oversaw the data collation and treatment of millions of men, many of whom were quartered year-round in camps crowded with the dead and dying. He became one of the first modern medical professionals.

Historian Aaron Crawford, postdoctoral fellow at the Center for Presidential History at Southern Methodist University, argues that the Sanitary Commission was a major move for public health. While some of Lincoln’s military staff objected to its meddlesome and strong-minded “lady nurses” who intervened in the camps, Lincoln eventually recognized and praised the commission in Washington for the conduct of its male and female volunteers. “As with all things Lincoln,” Crawford says, “it was a means to win the war.”

But the Union troops weren’t the only ones innovating in health care. By conscripting dentists and supporting dental care among the troops, the Confederate Army on the other side of the battle lines was responsible for the origins of modern dentistry.

James Garfield (1881)

James A. Garfield was the only sitting member of the House of Representatives ever elected president. But once he got there, he didn’t have much time to leave a mark. On July 2, 1881, four months into his presidency, Charles J. Guiteau, a disgruntled petitioner for a federal job, shot Garfield twice.

One bullet apparently lodged near his spine, and upon the recommendation of President Lincoln’s son—who happened to be at the train station where the assassination occurred—Garfield was treated by doctor Willard Bliss, who probed the abdominal wound with his fingers but found no bullet. Alexander Graham Bell was also brought in to locate the bullet with a primitive metal detector called an Induction Balance, but he couldn’t find it either.

Garfield died 79 days later, and, at Guiteau’s trial, the accused assassin claimed he had merely shot Garfield. “The doctors finished the work,” he said. Brandy Schillace, historian at Dittrick Museum of Medical History and author of Death’s Summer Coat, agrees with the assassin. Surgeons knew about Joseph Lister’s work advocating sterile surgery, but along with nine other physicians, Bliss prodded the president with unwashed fingers and unsterilized instruments, which probably introduced the infection that ultimately killed Garfield.

“Bliss had no respect for Lister’s antiseptic techniques, even though he knew about them,” Schillace says. “The aftermath of President Garfield’s passing made better antiseptic techniques a surgical necessity.” Garfield’s death led to the creation of the Secret Service, but Schillace argues that, more important, it offered a clinching public health anecdote that helped promote the germ theory of disease.

Lyndon B. Johnson (1963–1969)

The Social Security Act under Franklin D. Roosevelt had an enormous impact on people’s health, especially in rural areas. Roosevelt’s cabinet also founded the Office of Scientific Research and Development, which lubricated the industrial production of penicillin, medicine’s Manhattan Project. But historian Scott Podolsky, a primary care physician at Massachusetts General Hospital and the director of the Center for the History of Medicine at Harvard Medical School’s Francis A. Countway Library of Medicine, gives more points to Lyndon B. Johnson, who dramatically transformed the way the federal government funds health care.

Johnson established what have come to be known as Medicare and Medicaid. A direct role for the government in the health care system had been something of a lost cause up until then. The idea had been floated during Theodore Roosevelt’s presidential run in 1912, but the campaign failed. F.D.R. alluded to adequate health care in his Four Freedoms speech, but ultimately deemed it too controversial to include in Social Security. And when Harry S. Truman suggested the idea in the 1940s, the American Medical Association attacked it as a descent into “socialized medicine.”

Shortly before Johnson’s landslide election, he vowed to fight for medical care for the aged “as long as we have breath in our bodies.” It’s worth noting that America became the only country to create, in Medicare, a separate medical support system for the elderly. The bill was finally signed into law in 1965, and former president Truman, then 81 years old, received the first Medicare card.