manumission

/ˌmænyəˈmɪʃən/

Other forms: manumissions

In the United States before the Civil War, when owning slaves was common, manumission was the act of setting a slave free.

When Hamilton sings about "revolutionary manumission abolitionists" in the musical Hamilton, he's being a tiny bit redundant. Manumission and abolition are both used to mean "freeing slaves" or "a release from slavery." More specifically though, manumission is the act of a slave owner setting slaves free, while emancipation (and abolition) involve government action. When slavery was legal in the U.S., most who opposed it believed in all three.

Definitions of manumission

1. noun

   the formal act of freeing from slavery
   “he believed in the manumission of the slaves”

   type of:

   freeing, liberation, release

   the act of liberating someone or something