On 6 June 1884, Tesla first arrived in the US in New York City[26] with little besides a letter of recommendation from Charles Batchelor, a former employer. In the letter of recommendation to Thomas Edison, Batchelor wrote, "I know two great men and you are one of them; the other is this young man." Edison hired Tesla to work for his Edison Machine Works. Tesla's work for Edison began with simple electrical engineering and quickly progressed to solving some of the company's most difficult problems. Tesla was even offered the task of completely redesigning the Edison company's direct current generators.[27]

Tesla claims he was offered US$50,000 (~ US$1.1 million in 2007, adjusted for inflation)[28] if he redesigned Edison's inefficient motor and generators, making an improvement in both service and economy.[22]:5457 Tesla said he worked night and day on the project and gave the Edison Company several profitable new patents in the process. In 1885 when Tesla inquired about the payment for his work, Edison replied, "Tesla, you don't understand our American humor," thus breaking his word.[29][30] Earning a mere US$18 per week, Tesla would have had to work for 53 years to earn the amount he was promised. The offer was equal to the initial capital of the company. Tesla then immediately resigned when he was refused a raise to US$25 per week.[31]