The Northwest Territory eventually became Ohio, Indiana, Illinois, Michigan, and Wisconsin. Originally designated as such by Thomas Jefferson in 1784, these new federal lands were east of the Mississippi and lay between the Ohio River and the Great Lakes.
In 1787, the Northwest Ordinance mapped out the boundaries of each state. Of course, the topic of slavery had to be addressed as well, and it was decided that these states would not be open to slavery. There were roughly 60,000 settlers living in the area at the time to celebrate their new found statehood.
The inclusion of these five new states to the Union was significant because it created a precedence for the creation of new territory and the eventual annexation of additional states.