1. He only had two years of formal education.

The man considered the most brilliant American of his age rarely saw the inside of a classroom. Franklin spent just two years attending Boston Latin School and a private academy before joining the family candle and soap making business.

By age 12, he was serving as an indentured apprentice at a printing shop owned by his brother, James. Young Benjamin made up for his lack of schooling by spending what little money he earned on books, often going without food to afford new volumes. He also honed his composition skills by reading essays and articles and then rewriting them from memory.

Despite being almost entirely self-taught, Franklin later helped found the school that became the University of Pennsylvania and received honorary degrees from Harvard, Yale, the College of William and Mary, the University of St. Andrews and Oxford.

2. Franklin became a hit writer as a teenager.

After his brother James founded a weekly newspaper called the New England Courant in the 1720s, a 16-year-old Franklin began secretly submitting essays and commentary as “Silence Dogood,” a fictitious widow who offered homespun musings on everything from fashion and marriage to women’s rights and religion.

The letters were hugely popular, and Mrs. Dogood soon received several marriage proposals from eligible bachelors in Boston. Franklin penned 14 Dogood essays before unmasking himself as their author, much to his jealous brother’s chagrin. Sick of the toil and beatings he endured as James’ apprentice, the teenaged sensation then fled Boston the following year and settled in Philadelphia, the city that would remain his adopted hometown for the rest of his life.

3. He spent half his life in unofficial retirement.

Franklin arrived in Philadelphia in 1723 practically penniless, but over the next two decades he became enormously wealthy as a print shop owner, land speculator and publisher of the popular “Poor Richard’s Almanack.”

By 1748, the 42-year-old was rich enough to hang up his printer’s apron and become a “gentleman of leisure.” Franklin’s retirement allowed him to spend his remaining 42 years studying science and devising inventions such as the lightning rod, bifocal glasses and a more efficient heating stove. It also gave him the freedom to devote himself to public service.

Despite never running for elected office, he served as a delegate to the Continental Congress and the Constitutional Convention, diplomat and ambassador to France and Sweden, the first postmaster general and the president of the Supreme Executive Council of Pennsylvania.

Armonica invented by Benjamin Franklin. (Credit: Andreas Feininger/The LIFE Picture Collection/Getty Images)

4. Franklin designed a musical instrument used by Mozart and Beethoven.

Among Franklin’s more unusual inventions is his “glass armonica,” an instrument designed to replicate the otherworldly sound that a wet finger makes when rubbed along the rim of a glass. He made his first prototype in 1761 by having a London glassmaker build him 37 glass orbs of different sizes and pitches, which he then mounted on a spindle controlled by a foot pedal.

To play the instrument, the user would simply wet their fingers, rotate the apparatus and then touch the glass pieces to create individual tones or melodies. The armonica would go on to amass a considerable following during the 18th and early 19th centuries. Thousands were manufactured, and the likes of Mozart, Beethoven and Strauss all composed music for it.

Franklin would later write that, “Of all my inventions, the glass armonica has given me the greatest personal satisfaction.”

5. He was a reluctant revolutionary.

Franklin was among the last of the Founding Fathers to come out in favor of full separation from Britain. Having lived in London for several years and held royal appointments, he instead pushed for peaceful compromise and the preservation of the empire, once writing that, “every encroachment on rights is not worth a rebellion.”

When the Boston Tea Party took place in 1773, he dubbed it an “act of violent injustice on our part” and insisted that the East India Company should be compensated for its losses. Franklin had soured on the monarchy by the time he returned to the United States for the Second Continental Congress in 1775, but his past support for King George III earned him the suspicion of many of his fellow patriots. Before he publicly announced his support for American independence, a few even suspected he might be a British spy.

6. Franklin created a phonetic alphabet.

While living in London in 1768, Franklin embarked on a project “to give the alphabet a more natural order.” Annoyed by the many inconsistencies in English spelling, he devised his own phonetic system that ditched the redundant consonants C, J, Q, W, X and Y and added six new letters, each designed to represent its own specific vocal sound.

Franklin unveiled his “Scheme for a new Alphabet and a Reformed Mode of Spelling” in an essay published in 1779, but later scrapped the project after it failed to arouse public interest.

7. His son was a British loyalist.

Along with the two children he had with his wife, Deborah Read, Franklin also fathered an illegitimate son named William around 1730. The two were once close friends and partners—William helped Franklin with his famous kite experiment—but they later had a major falling out over the American Revolution. While Franklin joined in calling for independence from the mother country, William remained a staunch Tory who branded the patriots “intemperate zealots” and refused to resign his post as the royal governor of New Jersey.

He spent two years in a colonial prison for opposing the revolution, and later became a leader in a loyalist group before moving to England at the end of the war. The elder Franklin never forgave his son for “taking up arms against me.” He all but cut William out of his will, arguing, “the part he acted against me in the late war…will account for my leaving him no more of an estate he endeavored to deprive me of.”

DeAgostini/Getty Images DeAgostini/Getty Images

8. Franklin was a fashion icon in France.

In 1776, the Continental Congress sent Franklin to France to seek military aid for the revolution. The 70-year-old was already world renowned for his lighting experiments—the French even called their electrical experimenters “Franklinistes”—but his fame soared to new heights after his arrival in Paris.

Franklin capitalized on the French conception of Americans as rustic frontiersmen by dressing plainly and wearing a fur hat, which soon became his trademark and appeared in countless French portraits and medallions. Women even took to imitating the cap with oversized wigs in a style called “coiffure a la Franklin.”

When Franklin later traded the fur cap for a white hat during the signing of the 1778 treaty between the France and the United States, white colored headgear instantly became a fashion trend among the men of Paris.

9. He spent his later years as an abolitionist.

Franklin owned two slaves during his life, both of whom worked as household servants, but in his old age he came to view slavery as a vile institution that ran counter to the principles of the American Revolution.

He took over as president of a Pennsylvania abolitionist society in 1787, and in 1790 he presented a petition to Congress urging it to grant liberty “to those unhappy men who alone in this land of freedom are degraded into perpetual bondage.”

While the petition was ignored, Franklin kept up the fight until his death a few months later, and even included a provision in his will that required his daughter and son-in-law to free their slave to get their inheritance.

10. Franklin left Boston and Philadelphia an unusual gift in his will.

When he died in April 1790, Franklin willed 2,000 pounds sterling to his birthplace of Boston and his adopted home of Philadelphia. The largesse came with an unusual caveat: for its first 100 years, the money was to be placed in a trust and only used to provide loans to local tradesmen. A portion could then be spent, but the rest would remain off limits for another 100 years, at which point the cities could use it as they saw fit. Boston and

Philadelphia followed Franklin’s wishes, and by 1990 their funds were worth $4.5 million and $2 million, respectively. The two towns have since used the windfall to help finance the Franklin Institute in Philadelphia and the Benjamin Franklin Institute of Technology in Boston. Philadelphia also put some of its funds toward scholarships for students attending trade schools.

11. He’s a member of the International Swimming Hall of Fame.

Franklin had a lifelong love of swimming that began during his childhood in Boston. One of his first inventions was a pair of wooden hand paddles that he used to propel himself through the Charles River, and he wrote of once using a kite to skim across a pond.

While living in England in the 1760s, he displayed such an impressive array of swimming strokes during a dip in Thames that a friend offered to help him open his own swimming school. Franklin declined the offer, but he remained a proponent of swimming instruction for the rest of his life, once writing, “every parent would be glad to have their children skilled in swimming.” His aquatic exploits have since earned him an honorary induction into the International Swimming Hall of Fame.