The Thirteen Club
In the 1880s, the Thirteen Club was created to debunk the superstition of "13 at a table" being unlucky. This belief states that when 13 people are seated together at a table, one will die within a year. They met on the 13th of the month for a dinner served to 13 people at each table.
The "13 at a table" superstition may take its origin from The Last Supper wherein 13 people dined (Jesus and his twelve disciples) and Jesus died soon after, or from the Valhalla Banquet story in Norse mythology. That story tells about 12 gods invited to a banquet. Loki, making thirteen, intrudes and Balder, the favourite of the gods, is killed.
In New York at the December 13, 1886 meeting of the Thirteen Club, Robert Green Ingersoll ended his toast, "The Superstitions of Public Men":
|“||We have had enough mediocrity, enough policy, enough superstition, enough prejudice, enough provincialism, and the time has come for the American citizen to say: "Hereafter I will be represented by men who are worthy, not only of the great Republic, but of the Nineteenth Century.||”|
- Triskaidekaphobia (the fear of the number 13)
- Radford, M. & Radford, E. (1949) Encyclopedia of Superstitions 
- Lachenmeyer, N. 13: The Story of the World's Most Popular Superstition