Most people stop thinking about Thomas Edison after they learn he invented the incandescent light bulb. That's fine with me! However, he also invented many other things: Among his 1,093 patents were those for the phonograph, an early method of vacuum-sealing fruit, and scary dolls that spoke in high-pitched shrieks or Edison's own deep, adult male voice. According to historian Maury Klein, Edison was "probably the most brilliant inventor America ever had." While Klein notes in the same breath that he was also "capable of spectacularly wrong choices," this is a real understatement: In reality, Edison was a ruthlessly competitive businessman who sacrificed his relationships with his family, the wellbeing of many artists, and the lives of countless animals in his quest to dominate in his various endeavors.
Born in Ohio in 1847, Thomas Alva Edison developed an entrepreneurial spirit early; after he was pulled out of school for being hyper, he began selling candy and newspapers and conducting experiments with chemicals in his basement. (Because he stored these chemicals in a locker on a train, he can be said to have caused at least one train fire.) Despite a lack of formal schooling, he quickly went on to become the 19th-century version of a gray-hoodied college-dropout programmer; his first boon came in 1869, when at the age of 22 he earned $40,000 for an improvement on the stock ticker.
From there, Edison established a laboratory and went on a veritable inventing spree, though people on various forums argue that he deserves more credit for being a canny businessman and manager than for his skills as a scientist. The most notorious and sketchy of Edison's efforts towards world domination began in the early 1880s and would last for many years. Often referred to as the "War of Currents," the long-running battle between Edison and the industrialist George Westinghouse centered on which man would control the American electricity system. On one side, there was Edison, whose invention of the light bulb in 1879 was supported by a direct current (DC) electrical system of his own design. Although Edison knew the development of DC would stand to earn him hefty royalties as others used the system to generate hydroelectricity to power cities, he also feared DC's limitations: It couldn't travel long distances without losing a lot of energy. Opposing Edison was Westinghouse, who believed in another system: alternating current (AC), which the young Serbian engineer Nikola Tesla had originally developed for Edison. (Edison told Tesla his effort was cute but totally impractical, and sent him on his way.)
Once Westinghouse began setting up AC generators around the country, Edison started to get worried, so he initiated what Smithsonian magazine calls a "great political, legal and marketing game" to "ruin" Westinghouse. Part of this great game involved Edison staging live electrocution events—in which he used AC power to kill stray dogs, horses, and cattle—to make the point that his rival's current was too heinously dangerous for public usage.
Nice. Edison was ultimately wrong—AC is primarily what we use today—but he was able to take his hubris pretty far. While some biographers suggest that Edison might have genuinely believed AC was a menace unto society—he was really pure of heart!—no one disputes the fact that many of God's creations died because of his hell-bent convictions (or, you know, his megalomania). Near the turn of the century, Edison secretly funded the development of the world's first electric chair after Westinghouse refused to offer his generators to the enterprise; although Edison himself was against the death penalty, he wanted to prove his enemy's electricity was deadly. The first convicted murderer, William Kemmler, to be executed in the chair learned the hard way that brilliant inventor Edison was full of shit; it ultimately took two tries and several minutes to execute Kemmler, whose tortured agony and burning flesh sent spectators fleeing from the room.
On January 4, 1903, the War of Currents culminated in the spectacle electrocution of the Luna Park Zoo's cranky elephant Topsy, who had killed three people (including one trainer who tried to feed her a lit cigarette) and was deemed dangerous to humankind. The sad extant video of Topsy's execution offers a nice segue into Edison's other major vehicle for being a jerk: film. While Edison's poor judgment in the War of Currents is perhaps his most famous fuck-up—it incited a spate of back-and-forths when the Oatmeal published a comic portraying him as a villain and Tesla an angelic science unicorn in 2012—he was also a merciless thug who attempted a monopoly on the movie-making business. According to an episode of Cinefix's web series Film School'd, Edison was the original enemy of Prince, pirating countless film negatives (both domestic and international) and putting his name on them for profit. He took this so far as to establish "the Trust," a group of men hired to prevent the rolling of any camera that wasn't earning Edison money. They supposedly enforced their rule by firing bullets into cameras rolling on non-Edison productions.
On top of all this, of course, Edison was a hard-to-please father and neglectful husband. When his sons attempted to follow in his technological footsteps, the elder Edison would harshly criticize them for their failures; Thomas Sr. once called Thomas Jr. "absolutely illiterate scientifically and otherwise." Like many of history's great men, he was always in the laboratory, frequently forgetting anniversaries and birthdays. And although another son, William, studied at Yale, served in WWI, and invented new versions for spark plugs, Edison repeatedly told him he had "brought the blush of shame" to his cheek.