The Solidaridad collection dates from 1961 to 2007 and measures 7.5 linear feet in 20 boxes. The materials were compiled by Central America Solidarity Committee (CASC) members including Mike Henry, Mike Hutchinson, and Father Mike Colonnese. The collection includes Fr. Mike Colonnese's correspondence and papers relating to his personal and professional work. The bulk of the collection is comprised of bulletins, newsletters, periodicals, newspaper clippings, news alerts, posters, photographs, and ephemera gathered by the “three Mikes” during their work in Central America in the 1970s and 1980s.

The collection is arranged into the following series: Central America Solidarity Committee (CASC); Father Louis Michael Colonnese; Chile; El Salvador; Guatemala; Nicaragua; Latin America; Posters; and Audiovisual.

The Central America Solidarity Committee series (1981-2005) contains documents such as petitions, and ephemera of events organized at the University of Iowa and in the state of Iowa in support of Latin American countries.

Fr. Louis Michael Colonnese's series (1961-1992) includes personal and professional correspondence relating to the organizations he belonged to, his leadership position within the Catholic Church, and his advocacy work (particularly in Brazil, El Salvador, and Mexico).

The rest of the series are comprised of papers collected by the “three Mikes” and other Central America Solidarity Committee (CASC) members and are organized by country of origin and/or interest. The folders within each series are organized alphabetically and by date.

The Chile series (1962-1988) is primarily comprised of the “Solidaridad: compromiso con la verdad” periodical (in Spanish) from Santiago, Chile from the mid-1980s. Additional papers pertain to human rights activism and protest the dictatorship of Augusto Pinochet.

El Salvador series (1978-1995) consists of resource files regarding the Salvadoran Civil War, political conflicts, U.S. government interventions, human rights violations, and labor union advocacy. Several files are especially abundant in women’s activism and women-led organizations including the Committee of Mothers and Relatives of Prisoners, the Disappeared and the Politically Assassinated of El Salvador (COMADRES), Federación de Comites de Madres y Familiares de Presos - Desaparicidos y Asesinados Politicos de El Salvador (FECMAFAM), and Las Dignas: Mujeres por la Dignidad y la Vida.

The Guatemala series (1981-1990) is comprised of correspondence, bulletins, newsletters, pamphlets, periodicals and other publications, and testimonials. The series is completed by Guatemala’s Constitution and Labor Code, in Spanish, published in 1990.

The Nicaragua series (1981-1986) relates to the conflict between the Sandinistas and the Contras in Nicaragua in the 1980s. This series contains monthly reports from the Permanent Commission for Human Rights of Nicaragua, “Barricada International,” a weekly periodical by the Sandinista National Liberation Front, other publications, papers of religious organizations, and documents regarding the U.S. funding and military aid to the Contras in Nicaragua.

The Latin America series (1967-1999) consists of publications and various organization’s documents that focus on Latin America and/or Central America's social, economic, and political issues. It includes newsletters from the Washington Office on Latin America, critic publications on U.S. foreign policies and interventions in Latin America, as well as testimonies and creative writing works.

The Solidaridad collection is completed by photographs and slides of Mike Hutchison’s visits to El Salvador, posters, and audiovisual materials.