The Buttonwood Agreement, which took place on May 17th, 1792, started the New York Stock & Exchange Board (now called the NYSE, which is short for New York Stock Exchange). This agreement was signed by twenty-four stock brokers outside of 68 Wall Street in New York under a Button Wood tree. The organization drafted its constitution on March 8th, 1817, and named itself the "New York Stock & Exchange Board". In 1863 this name was shortened to its modern form, "New York Stock Exchange". Membership on the NYSE has been held as a valuable property since 1868. These days, members must purchase existing seats--which are now limited to a total of 1,366.
The Buttonwood agreement is honored by a regular online column written by the editors of The Economist newspaper.