To counterbalance research emphasis on conventional forms of political participation such as voting, discussing politics, and donating campaign money, the paper presents data from a crossnational study, conducted in 1974, of unconventional as well as conventional participation. "Unconventional participation" is interpreted as including an individual's potential for participating in a political protest activity as well as participation in voluntary association memberships which are not of an overt political nature. Part of a crossnational study to assess organizational membership impact on politics in eight western democracies, the paper reports only on data for the United States. Theoretical concerns of the study focus on changing trends in political protest, characteristics and motivation of individuals involved in protest, and the relationship between economic deprivation and political action. Survey respondents were asked to identify membership and classify level of activity in 19 types of organizations. Results were classified by sex, educational level, age, and race. An organizational activism index was created. Findings concerning the importance of organizational involvement for conventional participation are supported by the data. However, these analyses do not confirm the presumed impact of organizational involvement on reducing protest, dissatisfaction, and distrust in government. (Author/DB)