In 1938, the American architect Alfred Mosher Butts created the game as a variation on an earlier word game he invented, called "Lexiko". The two games had the same set of letter tiles, whose distributions and point values Butts worked out by performing a frequency analysis of letters from various sources, including "The New York Times". The new game, which he called "Criss-Crosswords," added the 15×15 gameboard and the crossword-style gameplay. He manufactured a few sets himself but was not successful in selling the game to any major game manufacturers of the day.