AC vs DC
Edison was a maniac about pushing his DC power. He claimed that AC was dangerous because of the high voltage, but it was his transmission of high amps (current) that was the real problem. He went so far as to gruesomely kill animals and a man on death row (in an electric chair) which he called the Westinghouse chair. (1) Westinghouse was financially backing Tesla’s AC power. AC, However, had one decisive advantage over DC:; it could be transmitted safely and efficiently over long distances.(2) Despite Edison’s best efforts, AC won out when Tesla lit up the Columbia exposition in Chicago, using his AC infrastructure.
1) Edison vs. Westinghouse: A Shocking Rivalry. Smithsonian. http://blogs.smithsonianmag.com/history/2011/10/edison-vs-westinghouse-a-shocking-rivalry/
2) AC/DC: What’s the Difference? PBS. http://www.pbs.org/wgbh/amex/edison/sfeature/acdc.html