Human beings have been selling stuff since, well, since there have been human beings. In the olden days, doing business meant swapping a flint ax for a bearskin coat. That would still define business today if it weren’t for these world-shaking innovations.

3000 B.C.: Money

For the first million years of business, selling meant barter, which meant the traded good had to be physically transported and traded. Money, on the other hand, allowed the value of goods to be traded rather than the goods themselves, thereby making it possible to sell mass quantities.

Fun fact: The largest coins ever “minted” are made of stone and weigh over four tons.

2700 B.C.: The Abacus

Money made large financial transactions possible, creating a need to quickly and easily calculate the amounts of goods and money being transacted. The first abacus was invented in Sumeria, but reached perfection in China.

Fun fact: Until around 1950s, a well-trained abacus-wielder could outperform an accountant with an adding machine.

1772 B.C.: Trade Law

Prior to Hammurabi’s invention of legal codes, the only way a seller could ensure that he actually got paid was to hire a private army and pummel the offending customer until he emptied his pockets.

Fun fact: Hammurabi makes a cameo appearance in the the Book of Genesis.

100 B.C.: Stock

The first publicly-held stock was in the Roman Republic, which allowed citizen to purchase and trade shares in private companies that provided government services. This innovation made average citizens into participants in the growing wealth of the republic.

Fun fact: The first stock market crash followed quickly on the heels of this invention.

27 B.C.: Interest

Economic activity grinds to a halt if buyers are limited to spending the cash they have on hand. The invention of interest, along with stock, turned Rome into the Wall Street of its day.

Fun fact: The ability to loan money on credit was crucial to the expansion of Roman Empire.

960: Paper Money

Up until this point, money consisted of metal coins with metallurgical value. Paper money made the value of money still more abstract, allowing it to represent precious metals being held in a vault in a central location.

Fun fact: Until the mid-20th century, it was possible to trade such paper for metals that it represented.

1129: Banking

The ability to deposit money in one place and withdraw it elsewhere allowed Crusaders to purchase supplies and weapons in the Holy Land rather carrying them from Europe.

Fun fact: The first bankers (The Templars) were burned at the stake. Wall Street, take note!

1494: Double Entry Bookkeeping

The Renaissance is known for the invention of the printing press, but arguably a more important business innovation took place when the entrepreneur Luca Pacioli figured out how to record profits and losses on the same sheet of paper.

Fun fact: The corporate “balance sheet” hasn’t changed much in over 500 years.

1642: The Adding Machine

The abacus was only good for adding and subtracting. The mechanical calculator, invented by the scientist Blaise Pascal, could repeat its operations, thereby making it easy to perform multiplication and division as well.

Fun fact: Pascal wasted most his life studying theology.

1714: The Typewriter

These once-omnipresent machines existed in various forms for over 150 years before they came into general business use.

Fun fact: The longest English word that you can type only using the letters in the top row is “typewriter.”

1818: The Trade Union

Trade unions brought the business world concepts like the 40-hour work week and worker health insurance, while restraining the worst impulses of laissez faire capitalism.

Fun fact: Unionized car manufacturers in Germany pay workers twice as much as U.S. manufacturers and yet are usually more profitable.

1823: The Telegraph

The information age arguably began with the ability to instantaneously transmit messages over long distances.

Fun fact: Prior to the telegraph, sending a message from the East Coast to the West Coast of the United States took a minimum of 10 days.

1837: The Programmable Computer

Charles Babbage’s Analytical Engine was a fully-programmable computer that foreshadowed the entire computer age and companies like IBM, which now provide the backbone of the entire business world.

Fun fact: The first programmer, Ada Lovelace, did not generally wear Dockers, sneakers, and a polo shirt.