The sheer daunting task of trying to locate your family over a period of several hundred years seems strangely impossible. You are staring at your Grandparent's names and not sure what to do next. Sometimes asking yourself questions or having a spreadsheet will help you uncover data or help you make sense of the work.
Do you have any family stories about your Grandparents that you can remember?
Do you know where they lived in the United states?
Have you tried locating them on the census?
If they came to that location, was it because that location was common for their Occupation?
Like - West Virginia was huge for Coal Miners. If they were Coal miners, their life expectancy was only about 40-50 years old. In 1907, 90% of the fatalities was due to the dangers of Coal Mining. It was our biggest asset for fuel and the technology was racing ahead of the factors and proper measures needed for safety. So try the following since it will be a long while until we can access the 1950 census.
If you don't know exactly when they died...
Have you tried searching for Obituaries?
Have you tried google?
Have you tried old directory listings (which used to name both the husband and wife and occupations) (found on ancestry.com)
Have you checked the cemeteries of the town of their last location on the 1940 census?
Have you tried gravefinder.com? findagrave.com?
Here are some links you can try:
about.com/Find A Grave by Name