I have successfully used these indexes to locate pertinent records. But I must offer some guidance as you use these indexes. First, all indexes can contain errors or omissions because they were made by humans. Merely because something is appearing on your computer screen does not mean that the computer checked the information for accuracy. Plus, how your family now spells your last name may not be how it was spelled 200 years ago, or how it looked to the person deciphering the handwriting to produce a neatly typed version.
Second, and this is very important, the indexes for deaths can be off by one year. This is because deaths in certain time periods were organized not from January through December of one particular year, but rather from July of one year through June of the following year. You need to follow through on an index entry by finding the original record to verify the name and date of death (and possibly learn names of parents and burial location).
Below is an example of the error in year. Eliakim Marsh died in Elizabeth, Union County, New Jersey on 15 January 1881. Here is his death certificate copied in Trenton at the NJDARM. (Remember that only the indexes are online. The actual records are housed in Trenton. You need to request a copy by mail or go in person.)
|New Jersey Division of Archives and Records Management|
Yet the indexes at Familysearch.org and now Ancestry.com have the year of death as 1880, off by one year.