The Americo-Liberian settlers did not relate well to the indigenous peoples they encountered, especially those in communities of the more isolated "bush". The colonial settlements were raided by the Kru and Grebo, from their inland chiefdoms. Encounters with tribal Africans in the bush often became violent. Believing themselves different from and culturally and educationally superior to the indigenous peoples, the Americo-Liberians developed as an elite minority that created and held on to political power. In a conscious effort to emulate the American South, the Americo-Liberian settlers adopted clothing such as  hoop skirts and tailcoats, and excluded natives from economic opportunities, including creating plantations on which natives were forced to work as slaves. Indigenous tribesmen did not enjoy birthright citizenship in their own land until 1904. Americo-Liberians encouraged religious organizations to set up missions and schools to educate the indigenous peoples.