Library of Congress call numbers group books by topic. The following are some you might find useful.
GN: Anthropology
HA: Social science statistics.
HM: Sociology (general and theoretical). Social psychology.
HN: Social history. Social problems. Social reform.
HQ: The family. Marriage. Women. Feminism.
HT: Communities. Classes. Races. Slavery.
HV: Social and public welfare. Substance abuse. Criminology.
J: Political Science
JA76: Political Sociology
JC: Political Theory
JK: Political institutions and public administration -- United States
JS: Local and municipal government, by country
K: Legal issues
LC: Education
