She also became active in other political issues. The Puerto Rican Feminine League, the first organization of its type to work for women's rights, was founded in 1917 by women of the "propertied, professional and intellectual elite", including Ana Roque de Duprey, Ángela Negrón Muñoz, and Matienzo, who were all teachers.Matías-Ortiz, Andrés (2001) Ambivalent Solidarities: Homeworkers, Needlework Unions, and the ILGWU in Puerto Rico, 1930-1940, University of Wisconsin-Madison, pp. 57 and 292 In this period women's rights groups were active throughout Latin America as well as in the United States.
