The Northwest Ordinance was a law passed by the Continental Congress in 1787 to establish a framework for governing the newly acquired territories north of the Ohio River. It outlined the process for admitting new states into the United States and set guidelines for land sales, education, and civil rights in these territories. The ordinance also emphasized the importance of public education and the prohibition of slavery in the new territories. It was a significant step in organizing the expansion of the United States and laid the groundwork for future statehood, influencing the development of the American frontier.