8 March 1817: The New York Stock Exchange gets its constitution

New York brokers adopted a formal constitution and named themselves the New York Stock and Exchange Board, the forerunner of the NYSE. They met indoors and set rules for trading, replacing the informal arrangement under a buttonwood tree on Wall Street. Trading volumes were tiny by later standards. From those modest beginnings grew the largest stock exchange in the world. Even Wall Street started small.

The lesson: Institutions that later seem permanent and enormous usually begin as modest agreements between a few people.