Before 1916 sometimes give state or county the person was born in. After 1915, there is a detailed form asking town born in, parents' full names, parents' places of birth, and spouse's name. Other questions, such as veteran status, number of years in the area, etc., are added in later years.
- Boone County Death Index through 1955 is at the Belvidere Library, the Family History Center, and the Rockford Public Library.
- Obituaries from 1851 through 1899 editions of the Belvidere newspaper are in book form (Helen Maxwell Williams) at the Belvidere Library.
- Gwen Anderson has almost completed extracting Belvidere obits from 1930 to 1955. Many deaths that occurred out of town can be found this way. Obits from the years before 1930 will be indexed in 1994. Winnebago County Death Index, through 1916, is at the Belvidere and Rockford Public Libraries and at the Family History Center. This index gives the full date of death. Rockford Public Library now has microfilm copies of vital records from the Winnebago County Clerk. Actual records are now available on microfilm at the Rockford Public Library.
- Indexes for both Winnebago and Boone Counties may be purchased from Ancestor Publishers. on microfiche.