Sarah and Miassar By Mrs.Weiss Jul 13, 1787 the Northwest Ordinance the Continual Congress passed the Northwest Ordinance Period: Mar 30, 1788 to Mar 31, 1789 Marietta, Ohio the Ohio company led settlers from New England, o Marietta, Ohio Sep 19, 1798 Marietta, courthouse and jail Marietta courthouse and jail was made.