The evolution of writing implement technology is a continuous and subtle one. Lewis Waterman opened up the possibility of portable pens with his invention of a practical fountain pen in 1884. But relatively quickly, users began working on a version that would be less likely to smudge ink everywhere, leading to the development of the modern ballpoint pen.

Independently, inventors around the world began developing the ball-and-socket technology—an American banker named John L. Loud received a patent on a less-than-perfect version as early as 1888—but generally, it's Hungarian brothers László and György Bíró who are credited with inventing the pen we still use today.

László, who is most often credited with the invention, was a journalist who theorized that by using newspaper ink in pens he could eliminate the characteristic smudging of fountain pens. Starting in the 1930s, he began experimenting with using the ink in fountain pens, but found that it was too thick to flow readily. His chemist brother, György, helped him perfect the ball-and-socket technology, and in 1938, László Bíró signed a deal with his early backer and business partner, Andor Goy, to produce and sell the pens in Hungary.

But tensions were rising as World War II loomed on the horizon, and rather than stay in his home country and profit off an invention that would soon be omnipresent, Bíró was forced to flee with his family, even selling off his shares of the fledgling company to fund their travel.

After failing to find refuge around Europe, Bíró landed in Argentina, where he finally filed for a patent on his ballpoint pen. The patent was awarded on June 10, 1943, the anniversary of which is celebrated as National Ballpoint Pen Day—but the story didn't end there.

Argentinian pen ad. Wikimedia Commons // CC BY-SA 2.5

Henry Martin, an English accountant living in South America, offered to back Bíró's project, which he thought might be of military interest. Unlike the traditional nib pens, which leaked in flight, Martin believed the ballpoint pens would work just as well in the air as they did on land, making them the perfect solution for a nagging air force issue.

Martin demonstrated the ballpoint's ability for the Royal Air Force in London and the U.S. Air Force in Washington, D.C. Both were impressed, and after material rations were negotiated, the pens went into production. When the War ended, ballpoint pens went into commercial production in 1945. The public instantly fell in love. When they were first on the market, the Reynolds Rocket—America's first ballpoint pen—sold for $12.50 (about $150 today). And yet, in their first five months of existence, the Reynolds International Pen Company reported selling 1.5 million pens, requiring them to up production from 70 units per day on October 7, 1945 to 30,000 units per day the following February.

Sadly, Bíró never got rich off his invention. He fared better than Goy—who had remained behind in Hungary, where he became embroiled in a number of costly lawsuits when the country nationalized his company—but in 1945, he sold the patent to Marcel Bich, who founded Bic pens. However, his role in the ballpoint pen's conception lives on with the celebration of Inventors Day on his birthday, September 29, in Argentina, and in the word for "pen" in Argentina: birome.