Vital records are "certificates or reports of birth, death, marriage, declaration of domestic partnership, dissolution of marriage or domestic partnership and data related thereto" (Oregon Laws legal dictionary).
For certified copies:
For genealogical copies:
Request the above via the Genealogy Unit of the Cook County Clerk's Bureau of Vital Records (note: this site requires users to create a free account).
Birth certificates for the years below are available in full-text online:
For divorce, probate, and other court records, please contact Circuit Court of Cook County.
For military, immigration and naturalization records, and census information, please contact National Archives and Records Administration-Great Lakes Region.
The Cook County Coroner's Inquest Record Index is available from 1872-1911.
Records after 1911 are in the Office of the Medical Examiner.
Family Search has a Wiki on searching for Illinois Naturalization and Citizenship records. (This site is free but you may need to create an account. This is an external resource.)
We also have published, photographic, and archival material about immigration in Chicago. These materials include welcome books, papers of politicians, oral history projects, etc.
The Newberry Library's Adoption Research Guide lists various resources from their collection as well as external links related to the adoption process for adoptees, adoptive parents, and birth relatives.
Search by Subject Heading to find items in the research collection. (This list is not exhaustive).
Adoptees and adoptive parents of youth formerly in the care of the Illinois Department of Children and Family Services can learn more about the availability of their records by contacting the records administrator.