Final answer:
When a territory's population reached 60,000 inhabitants, it could draft its own constitution and apply to join the United States as a new state according to the Northwest Ordinance of 1787.
Step-by-step explanation:
When the territory reached 60,000 inhabitants, its settlers could draft their own constitution and ask to join the United States as a new state.
The Northwest Ordinance of 1787 outlined the process for a territory to become a state, which included specific population thresholds and administrative procedures during the period of territorial growth. Once a territory attained a population of 60,000, it could frame a state constitution, which had to include the forbiddance of slavery and the protection of religious freedom. Then it could apply for admission to the Union as a full-fledged state, a status that would grant the inhabitant's self-governance under the United States federal system.