Where did The Missouri Compromise decide the legality of slaves in the new states?

The Missouri Compromise, enacted in 1820, established a line at 36°30' latitude, north of which slavery would be prohibited in the territories of the Louisiana Purchase, except for Missouri itself. This compromise aimed to maintain a balance between free and slave states in the Union. Thus, it effectively decided that new states north of the line would be free states, while those south could allow slavery.