Theodore Roosevelt, force of nature and future president, was the vice president on Sept. 14, 1901, when President William McKinley died of gunshot wounds inflicted by the anarchist assassin Leon Czolgosz eight days before; and he was only that because members of the New York State Republican Party were desperate to get Roosevelt, the governor, a reformist force of nature, out of their hair.

There is case to be made that such accidental presidents, as one author labels them in a recent study, can be greater than the ones we elect because they come into office without having to pander or compromise to win votes. The case can be rested on Roosevelt’s career.

McKinley, the last president to have served in the Civil War, a son of frontier Ohio, was elected in 1896 to hasten recovery from the panic of 1893 and keep the economy humming while deploying tariffs on imported goods, all of which he did, leading to his re-election in 1900 and then his fateful meeting with Czolgosz in Buffalo, New York, where McKinley was attending the Pan-American Exposition.

Theodore Roosevelt departed from his patrician upbringing in the 19th century by taking an interest in electoral politics. At 23, he became the youngest member of the New York State Legislature, where he made a name with a flurry of progressive bills and by challenging anyone who insulted him – he was a dandy – to a fist fight. He spoke of industrialists and financiers as “the wealthy criminal class.” Republican boss Tom Platt wanted none of it, but the press, as Jared Cohen notes in “Accidental Presidents,” found Roosevelt “both fascinating and ridiculous.”

After the death of his mother and his first wife, Roosevelt briefly retired from politics in 1884 and took up cattle ranching in the Dakota Territory. He wasn’t especially good at it but he did it with gusto and forever after would tell anyone who would listen that the strenuous life of a cowboy imparted “the stern, manly qualities that are invaluable to a nation.” Returning East, he was made president of the Board of New York City Police Commissioners, where he exerted himself to ensure officers were actually walking their beats (this was novel) and that recruits were appointed based on their qualifications rather than their political connections. Platt was still not amused.

As governor, Roosevelt further antagonized Platt with civil service reforms. When Vice President Garret Hobart died, in 1899, Platt saw his chance to kick Roosevelt upstairs to McKinley’s re-election ticket. “I want to get rid of the bastard,” Platt said. “I want to bury him.”

But it was McKinley who was buried, six months into his second term, making Roosevelt, at 42 and brimming with energy, the youngest person to become president.

Mark Hanna, McKinley’s political ally and a party boss in his own right, had pushed back against Platt and having Roosevelt on the ticket. “Now look,” he said, when McKinley was dead, “that damned cowboy is president of the United States!”

Roosevelt, writing to a friend, said, “It is a dreadful thing to come into the presidency this way; but it would be far worse to be morbid about it.” He intended to make the most of what he dubbed the bully pulpit, meaning a terrific platform, for a man who, as his daughter Alice once observed, “wants to be the bride at every wedding, the corpse at every funeral and the baby at every christening.” He used it to remake the country in his progressive image. And when he won election in 1904, he proudly told his second wife, “I am no longer a political accident.”