The legislation that banned slavery in the Kansas Territory was the Wyandotte Constitution. This constitution, adopted in 1859 by the Free State delegates in Kansas, explicitly prohibited slavery in the state of Kansas.
The other options you mentioned are significant in the context of slavery and the territories but did not specifically ban slavery in the Kansas Territory:
- The Kansas-Nebraska Act (1854) allowed the territories of Kansas and Nebraska to decide for themselves whether to allow slavery through the principle of popular sovereignty.
- The Missouri Compromise (1820) established a line dividing free and slave territories but was not specific to the Kansas Territory and was effectively repealed by the Kansas-Nebraska Act.
- The Compromise of 1850 dealt with various issues related to slavery but did not specifically address slavery in the Kansas Territory in a way that banned it.
Therefore, the correct answer is the Wyandotte Constitution.