With Donald Trump just weeks from his inauguration, political commentators are making much of the fact that the White House will soon have a businessperson in residence for the first time in recent memory.

Yet, President-elect Trump is far from the only occupant of the Oval Office to know his way around a profit and loss statement.

The private sector, and small business in particular, has produced a fair share of presidents, going all the way back to George Washington. The "Father of Our Country" was also among its earliest entrepreneurs, with a portfolio of businesses that included planting, milling and whiskey distilling.

Many other presidents grew up in families with small businesses. Calvin Coolidge was the son of a Plymouth Notch, Vermont, storekeeper, Herbert Hoover of a West Branch, Iowa, blacksmith. Richard Nixon's family ran a combination grocery store and gas station in Whittier, California. Gerald Ford's stepfather had a small paint and varnish company in Grand Rapids, Michigan.

"Owning a small business provides an opportunity for people to practice developing their emotional intelligence for reading people, building bonds with them and knowing how to motivate them," said Will Swift, a presidential historian and practicing clinical psychologist whose most recent book is "Pat and Dick: The Nixons, An Intimate Portrait of a Marriage."

"With the right character, a future president can learn from setbacks and develop grit — the quality of perseverance that allows them to keep on trucking after a setback," Swift added.

Here, in chronological order, are three 20th century presidents who made the move from running their own businesses to running the nation, with some admittedly mixed results.

Warren G. Harding (29th president, 1921 to 1923)

Warren G. Harding Warren G. Harding managed a well-liked newspaper before becoming president of the United States. (Photo: Harris & Ewing/Wikimedia Common)

Before he entered politics, Warren G. Harding was the owner and publisher of a small newspaper in central Ohio, the Marion Star. Harding and two friends bought the struggling paper for $300 in 1884, and under Harding's stewardship it soon became a financial success.

The turnaround, according to an account published by the Miller Center at the University of Virginia, was due largely to "Harding's good-natured manner. His paper became a favorite with Ohio politicians of both parties because of his evenhanded reporting. He never ran a critical story if he could avoid it. His employees also loved and respected him for his willingness to share company profits with them. In his entire career, he never fired a single employee."

Harding sold the paper in 1923, shortly before his death. It is still published today, as part of the Gannett newspaper chain.

The affability that served Harding well in business helped make him a popular president during in his lifetime. Unfortunately, it also left him ill-prepared to control his greedier associates. Although Harding's sudden death in 1923 spared him many of the revelations that would follow, his administration is best remembered today for the Teapot Dome scandal, probably the biggest blot on the presidency until Watergate.

Privately, even Harding questioned whether he was right for the job. "Frankly, being president is rather an unattractive business unless one relishes the exercise of power," he wrote a friend. "That is a thing which has never greatly appealed to me."

It's easy to imagine that he might have been happier back in Marion, Ohio, running his newspaper.

Harry S. Truman (33rd president, 1945 to 1953)

Harry S. Truman Harry Truman briefly ran a men's clothing store in the 1920s. (Photo: Edmonston Studio/Wikimedia Commons)

After returning to his native Missouri at the end of World War I, Truman and an army buddy, Eddie Jacobson, opened a men’s clothing and hat store in downtown Kansas City. By most accounts, the shop was a success from the start, but an economic downturn in the early 1920s caught the partners with too much inventory purchased on credit. After selling off as much as they could at bargain prices, they shuttered the store for good in late 1922.

For Truman, the experience wasn't a total loss, however. As a store owner he'd been active in the local business community, and the connections he made there would prove valuable as he built a career in politics.

Asked later in life whether he liked being in the retail business, Truman said he never had time to give it much thought — he was too busy trying to make a living and support his family. Nor, he said, did he have time to complain about how it eventually turned out. "You'll notice if you read your history," he added, "that the work of the world gets done by people who aren't bellyachers."

Jimmy Carter (39th president, 1977 to 1981)

Jimmy Carter's official White House photograph Jimmy Carter owned a peanut farmer before he entered the Oval Office. (Photo: White House/Wikimedia Commons)

In his 1976 presidential bid, James Earl "Jimmy" Carter made the most of his background as a peanut farmer from Plains, Georgia; his campaign workers were even known as the "Peanut Brigade."

Carter had left the Navy to return to Plains and take over the family business after his father's death in 1953. Though once prosperous, the business, which also consisted of a warehouse and farm-supply store, was then producing so little income that Carter and his wife, Rosalynn, had to live in a public housing project until they could get it solidly profitable again. Their gross income the first year was $280, he later recalled, and that included their unpaid accounts receivable.

With his election as president two decades later, Carter put the business into a blind trust. Unfortunately, when he was about to leave the White House, he would discover that a combination of "inept management and three years of severe drought" had left the business deep in debt, as he described it in a recent memoir. He sold the warehouse to a large agribusiness company, but managed to hang onto the family farmland.

Carter reminisced about the key lessons he'd learned growing up in the family business and ultimately heading it, in a 2015 Wall Street Journal interview: "Working with my father in the fields taught me to be tenacious," he said. "I also learned to hunker down, take the duties that come to me, do the best I can and not worry about the consequences. A lot of the lessons I learned as a plowman still come in handy."