Benjamin Franklin was born in Boston on January 6, 1706. He was the eleventh child of Josiah Franklin, a candle maker; his mother was named Abiah. Franklin's father put him in grammar school to become a minister, but soon took him out again because he could not afford it. Franklin spent a year at a different school and then became an apprentice in the printing shop of his older half-brother, James. There he learned the trade and anonymously published series of essays in his brother's paper.

When James and Benjamin had a falling out, Franklin left James's shop and moved to Philadelphia. In Philadelphia he found work in another printing shop, and a year later sailed to London to buy supplies to start his own shop. Franklin was stranded in London when the letter of credit the governor of Pennsylvania had promised him never arrived. Unable to afford passage back to America, Franklin found work in a London printing shop, writing more essays and an anonymous pamphlet. After two years, he returned to Philadelphia to work for a merchant, and then finally set up his own printing shop.

In 1730, Franklin won a contract from the government for official printing work. With this income he was secure, and he soon bought a failing newspaper from his former boss. He married Deborah Read, the daughter of the couple he had lived with when he first arrived in Philadelphia. Together they raised Franklin's illegitimate son, William, and had two children of their own.

During the 1730s, Franklin was active in civic projects, founding the first public library and the first fire company in America. He also began publishing his popular Poor Richard's Almanack, full of wise and funny sayings. In the 1740s, Franklin grew interested in science, especially the study of electricity. He conducted a series of experiments and discovered that lightning is electrical. His discoveries made him famous in Europe as well as America.

In 1748, Franklin retired from the printing business and devoted himself fulltime to science and civic leadership, founding a hospital and a volunteer militia. In 1751, he was elected to the Pennsylvania assembly, where he quickly rose to power. When war with the French and Indians threatened in the mid-1750s, Franklin attended a meeting of colonial governments in Albany, where he drafted the Albany Plan of Union.

Two years later, Franklin organized another militia, and then in 1757 sailed to Britain as a representative of the Pennsylvania assembly. There he tried to convince the British government to let the assembly tax Pennsylvania's proprietors. He returned in 1762 and soon faced a crisis when the Paxton Boys marched on Philadelphia. He became more deeply involved in Pennsylvania politics, leading a campaign to change Pennsylvania from a proprietary colony to a royal one.

This mission took Franklin back to Britain in 1764. Once he was in London, however, he spent most of his time trying to block, and then repeal, the Stamp Act. He also visited France, Scotland and Wales, became president of the American Philosophical Society, and began writing his Autobiography. Three other colonies appointed Franklin as their representative in London, making him a sort of unofficial American ambassador to Britain.

Though Franklin's arguments against the Stamp Act helped in getting it repealed, he could not keep America and Britain from drifting toward war. In 1773, he was caught up in a scandal involving letters sent from the governors of Massachusetts to British authorities. When these letters–which requested military help from the British against the colonists–were published, Americans were outraged. Franklin took the blame for stealing the letters and was branded a thief by the British. A little over a year later, Franklin left Britain for good, convinced that war was inevitable.

Franklin returned to Philadelphia just as the Revolutionary War was beginning. He jumped into the cause, attending the Second Continental Congress and helping Thomas Jefferson write the Declaration of Independence. Franklin drafted a radically democratic Declaration of Rights for Pennsylvania (which was not adopted) and argued for proportional representation in the Articles of Confederation.

In 1776, Congress appointed Franklin a commissioner to France, where in 1778 he helped negotiate a Treaty of Alliance with the French. In 1782–1783 he negotiated the peace treaty between Britain and America that ended the Revolutionary War. Returning to America in 1785, Franklin was elected to the executive council of the Pennsylvania government, where he served for three years. He attended the Constitutional Convention in 1787 and retired for good in 1788. In his last years he became an ardent foe of slavery. He died on April 17, 1790, aged 84.