Super Mario Bros. is one of the most successful games ever released, but no one can prove its exact release date in the US.
In a fantastic investigation by Gamasutra's Frank Cifaldi, we get a glimpse into just how poorly the release of what is arguably the most well-known game of all time was documented. We know when the game was released in Japan (September 13, 1985), but no one can agree on a date for US.
Most of our history books — and there just aren't that many yet, sadly — tell us that Super Mario Bros. did not come to America until 1986. Most famously, Steven Kent's The Ultimate History of Video Games specifically calls out that the game "had not been introduced" when the system debuted in New York. Chris Kohler in his book Power-Up: How Japanese Video Games Gave the World an Extra Life says that game "arrived in 1986." Tristan Donovan, in Replay: The History of Video Games (a personal favorite) goes as far as to say the game came out in the United States very specifically in March, 1986.
Before we go on, it should be noted that Nintendo has an internal launch date for both the NES and Super Mario Bros.: October 18, 1985. For most that would be the end of it: we have an official source stating an exact date, end of story. But I want to know where that date came from, and what it actually means. Besides, Nintendo has been wrong about its own history before.
Cifaldi's search for a paper trail is an incredibly interesting read and strongly recommend reading the full story over at Gamasutra.