Assertion: party's leader | /r/CapableOf | join force
Facets:
value: to oppose the extension of slavery
type: PURPOSE
Source sentences:
text: The Republican Party traces its roots to the 1850s, when antislavery leaders (including former members of the Democratic, Whig, and Free-Soil parties) joined forces to oppose the extension of slavery into the Kansas and Nebraska territories by the proposed Kansas-Nebraska Act.