Focus ᎾᎿ ᎯᎠ slavery ᎢᏳᏍᏗ ᎧᏃᎮᏗ ᎤᎭ ᏭᏪᏙᎢ cyclical. ᏂᏛᎴᏅᏓ 1900 1955, historians ᎠᎦᏎᏍᏔᏅ anti-slavery agitation ᎾᏍᏋ ᎦᏲᎵᎨ ᎤᎵᏍᎨᏛ ᎬᎾᏬᏍᎬ constitutional, ᎠᎳᏏᏅᏙᏗ, ᎠᎴ cultural ᎠᏯᏙᎯᎲ. ᎣᏂ ᏧᏩᎫᏛ ᎯᎠ 1960s historians ᎤᎭ ᎠᏏᏇ emphasized slavery ᎠᎴ antislavery ᏥᏄᏍᏗ ᎯᎠ ᎢᎬᏱ ᎠᎴᏅᏗ ᏂᎬᏂᏏᏍᎬ ᎯᎠ ᏓᏄᏩ, ᎬᏙᏗ Ꮝ ᎤᎪᏗᏗ ᎠᏙᏱᏯᏛ ᎠᎬᏩᎵ, ᎠᎳᏏᏅᏙᏗ, constitutional ᎠᎴ ideological dimensions.