Surely the ­best-­known fact about Theodore Roosevelt is that he was a sickly boy who transformed himself into a burly, fearless specimen of masculine strength. The makeover began with a humiliation. He was 13, traveling by stagecoach to a lake in Maine to recuperate from a bout of asthma, when he ran into a pair of bullies. Apparently finding him too puny to rough up, they merely toyed with him. Telling the story years later, he said he had vowed that he would never again “be put in that helpless position.” Boxing lessons ­followed.

Some Roosevelt biographers say that too much has been made of the showdown, but there is no denying that his memories of the bullies and his own helplessness lived on. His creed of the strenuous life was a warning that comfort and luxury could make a country slack, stupid, and vulnerable to the predations of the strong. The big-stick diplomacy of his presidential years (1901–09) was a weapon against potential aggressors. And the Square Deal, his economic agenda, can be seen as an effort to protect the defenseless from the bullies of ­capitalism—­monopolists, inhumane employers, stock waterers, grabbers of public ­lands.

Lincoln Steffens, a ­reform-­minded journalist who had met Roosevelt long before his presidency, inadvertently gave the agenda its name. Steffens interviewed TR often and knew that he fancied himself a reformer too. Peeved by the caution of TR’s first year in office, Steffens tried to embarrass him into action. “You don’t stand for anything fundamental,” Steffens told him one day at the White House. “All you represent is the square deal.”

Roosevelt, plainly overjoyed, leapt out of his chair, pounded his desk, and bellowed, “That’s it. That’s my slogan: the square deal.”

To Steffens, a square deal was a mere transaction, all process and no content. But TR saw instantly that the words captured a universal yearning: Who didn’t want to be dealt with ­squarely?

There was just one hitch: The bullies had long been accustomed to holding the aces, and the senators and representatives they sent to Congress ensured that the deck remained stacked. The most egregious special favors were embodied in a tariff that imposed high taxes on most goods made abroad. In this ­pre–­income ­tax era, the tariff was the federal government’s major source of revenue, but American manufacturers also exploited it to protect themselves from foreign competition. Prices and profits rose. Wages did ­not.

Congress occasionally talked of reforming the tariff but always stopped short of action. Bills to improve the lot of the working class were shouted down as violations of labor’s freedom to make its own bargains with employers. The courts helped too, by overturning laws at odds with the reigning principle of laissez faire and issuing injunctions against strikes on the ground that they deprived employers of the use of their ­property.

TR tried to assure the bullies that the Square Deal was not socialism. He did not plan to confiscate the aces and give them to the poor, he said; he meant only to prevent crookedness in the dealing. He had no objection to men of great wealth, only to the “malefactors of great wealth,” as he would call them. He didn’t name names, but the press was soon slapping the label on J. Pierpont ­Morgan and every other tycoon who ran into trouble with the trust buster. TR also declared that he would not tolerate demagogues who incited the ­have-­nots to violence against the haves. From his presidency through his run for a third term in 1912, he would denounce class envy in one breath and in the next opine that “of all the forms of tyranny the least attractive and most vulgar is the tyranny of mere wealth.”

On the legislative front, the Square Deal proved a modest success. Roosevelt won stricter regulation of railroads, made employers liable for work injuries caused by management’s negligence, banned the adulteration and mislabeling of food and drugs, and pushed through the Meat Inspection Act, which created a sanitary patrol for ­slaughter­houses.

TR’s noisy pride in taking on the bullies naturally attracted snipers. They pointed out that he did nothing about the tariff, that his trustbusting did not slay the beast of monopoly, and that some of the new laws were not progressive. The Elkins Act, for example, ended the ­cut-­rate pricing that railroads had given their largest shippers. The change did help the small ­shippers—­but not nearly as much as it helped the railroads. Once the president signed the bill in 1903, the railroads proceeded to charge everybody full freight. Merrily they rolled ­along.

Roosevelt’s successes were more impressive when he could act without Congress, as he did in the coal strike of 1902 (and many times afterward, prompting one newspaperman to say that TR had no more respect for Congress than a dog has for a marriage license). As the strike dragged on and coal supplies dwindled, the price sextupled. Fearing that winter would bring riots and leave the poor to freeze to death, Roosevelt asked the mine owners and the union to come to terms, for the good of the country. They refused. The president had no constitutional authority to intervene, but he did something unprecedented: He called both sides to Washington and kept at them until the miners agreed to go back to work while an arbitration panel reached a settlement that would bind both sides. Wall Street harrumphed about his disregard of property rights, but his intervention drove home his point that in a world of concentrated power and wealth, only the federal government had enough muscle to check the abuses of the ­bullies.

In 1912, when TR founded the National Progressive Party (better known as the Bull Moose) to make another run for the White House, he positioned himself far to the left of the Square Deal. He did so to woo voters, of course, but he had also come to believe that socialism, which he abhorred, would lose its appeal if the bullies of capitalism were stopped. He called for a living wage, workers’ compensation, a ban on child labor, an end to the ­seven-­day workweek, and broad authority to regulate big business.

The Socialist Party accused TR of stealing its best ideas and watering them down to make capitalism seem more benign than it was. The suspicion was not entirely wrong. As Lincoln Steffens might have told them, stealing ideas was one of Roosevelt’s great political strengths. Another was his readiness to plant himself between the ruthless and the helpless. The boy had overcome his weakness, and the man recognized that such conquests were not always possible or ­permanent.

TR’s decision to fight the bullies in the middle of the political road frustrated progressives hoping for more change and irritated conservatives devoted to the status quo. He understood that, but as he once wrote a friend, he hoped that whatever his critics thought, “the average American citizen, the man who works hard, who does not live too easily, but who is a decent and upright fellow, shall feel that I have tried to the very best of my ability to be his representative.”

His enormous popularity in his own time indicates that ordinary people did feel they had a champion in Theodore Roosevelt, and his great popularity ­now—­among conservatives and progressives ­alike—­suggests that a square deal is a good thing for just about all of the people, just about all of the ­time.