If the GI father you have been searching for is deceased, the following information may be of assistance in tracking down some further information or family members:
You could also try going to: http://ssdi.genealogy.rootsweb.com Put in his first and last name, leaving out the middle name/initial. See if you get a match. If you get too many look for a match with date of birth or date of death. There is also an advanced search feature. This may get you a Social Security Number. You will probably get a last residence (City, County, State and ZIP Code).
Go to a search engine, such as www.yahoo.com and type in the name of the state (e.g., Florida, Nevada, Maryland) and the following words <Department of Vital Records>. You will then get some state government web sites where for a small fee you may be able to obtain a copy of a death certificate.
For a few more dollars/pounds/euros, you can go direct to: http://www.vitalchek.com and obtain information for all states. The death certificate may list a relative, place of burial, cause of death, etc. Sometimes this will not work because the GI did not die in his home state, but may have been on holiday (vacation) elsewhere.
In most cases, he will have been buried in his hometown so again using a serach engine such as www.yahoo.com search on the name of the city or county (e.g., Chicago, Jackson, Bozeman) and the words <Public Library>. You should then get some matching web sites. Find a way to send an e-mail to the librarian or research department, provide the GI's full name and date of death and ask about getting a copy of an obituary from the community newspaper.
If the library doesn't work out, use the search engine again and input the name of the city and state and the word <newspaper> to try and find a local newspaper. Send them an e-mail asking for a copy of the obituary.
Use www.teldir.com and one of the online U.S. telephone directories to search on the last name and city and state of the person you are seeking. You may find that relatives still live in town and you may get some names, addresses and phone numbers.
Also use www.teldir.com to search for the funeral home (listed on the death certificate) and call/write for more information.