The National Institute for Computer-Assisted Reporting (NICAR) has forty-seven (47) databases for sale in bulk or by geographic region.
Data sets range from “AJC School Test Scores” and “FAA Accidents and Incidents” to “Social Security Administration Death Master File” and “Wage and Hour Enforcement.”
The data sets cover decades of records.
There is a one hundred (100) record sample for each database.
The samples offer an avenue to show what more is possible with topic maps, to paying customers based upon a familiar dataset.
With all the talk of gun control in the United States, consider the Federal Firearms/Explosives Licensees database.
For free you can see:
Main documentation (readme.txt)
Sample Data (sampleatf_ffl.xls)
Do remember that NICAR already has the attention of an interested audience, should you need a partner in marketing a fuller result.