The interchangeability of the two spellings can be found in a series of "National Donut Week" articles in "The New York Times" that covered the 1939 World's Fair. In four articles beginning October 9, two mention the "donut" spelling. Dunkin' Donuts, which was so-named in 1950, following its 1948 founding under the name Open Kettle (Quincy, Massachusetts), is the oldest surviving company to use the "donut" variation; other chains, such as the defunct Mayflower Doughnut Corporation (1931), did not use that spelling. According to the Oxford Dictionaries while "doughnut" is used internationally, the spelling "donut" is American. The spelling "donut" remained rare until the 1950s, and has since grown significantly in popularity; this growth in use has possibly been influenced by the spread of Dunkin' Donuts.