A good place to start is the Social Security Death Index for the state in which the person passes away. You can GOOGLE this and it's free. GOOGLE will also show sites which will find information for...
Your local library may have records if it were reported at the time. Most libraries have local newspapers available for you to scan if you have some idea of the time period. Or ask neighbors and...
Contact the Probate Court in the jurisdiction where the person lived. In England, all executed wills are a matter of public record. Depending on when the death occurred, and what your objective was,...