Three relevant pieces of research about social movement leadership:
Classic: Robnett, Belinda. 2000. How long? How long?: African-American women in the struggle for civil rights. Oxford University Press.
Review: Morris, Aldon and Suzanne Staggenborg. 2004. “Leadership in Social Movements” Pp. 171-96 in The Blackwell Companion to Social Movements, edited by D. A. Snow, S. A. Soule and H. Kriesi. Oxford: Blackwell Publishing.
Contemporary: Nepstad, Sharon and Clifford Bob. 2006. “When Do Leaders Matter? Hypotheses on Leadership Dynamics in Social Movements.” Mobilization: An International Quarterly. 11(1):1-22.
Andrews, Kenneth T., Marshall Ganz, Matthew Baggetta, Hahrie Han, Chaeyoon Lim. 2010. “Leadership, Membership, and Voice: Civic Associations That Work.” American Journal of Sociology 115(4): 1191-1242.