If your ancestor worked for US railroads, their social security information can be found under the Railroad Retirement Board records. The first three digits of their Social Security Numbers range from 707 to 728.
Public record keeping was very unorganized in previous generations.
You need to start to collect pictures of your family and the places they have lived.
Immigration is entering a country where you are not a native to take up permanent residence. Emigration is leaving a country where you have been a citizen.
Look for the archival label on storage products - "acid free" or 'archival safe".
An ancestor is a person from whom a person is descended, e.g. parent, grandparent, great-grandparent.
Be sure you cite your sources!
[Sources - Citations]