Complex sentence: The more traditional, non-slave-owning members of the tribes most deeply resented the sale of their lands to whites; however several traditionalist groups, such as Pin Indians and the intertribal Four Mothers Society, were outspoken opponents of slavery during the Civil War.
Split into simpler sentences: The more traditional, non-slave-owning members of the tribes most deeply resented the sale of their lands to whites. Traditionalist groups, such as Pin Indians and the intertribal Four Mothers Society, were outspoken opponents of slavery during the Civil War.