Let's start with what we do know.
Born: 7 July 1891, AL
Died: 13 Aug 1956, Imperial Co. CA
Source: California Death Index 1940-1997
Do you have a copy of his obituary? The daughter's name should be in his obit and maybe her mother's name too.
Do you have a copy of his death certificate? If the Informant knew where he was born in Alabama, it will be on his death certificate. Also his daughter might have been the Informant, therefore, her married name will be on it too.
Since Samuel was born in 1891, they didn't move to California in a covered wagon. Sounds like they moved to somewhere in Texas, Anna was born there and then on to California. However I don't find either one of them in Texas nor in California except for his death info.
If Anna' birth certificate doesn't say what county she was born in (which is very odd) but her mother's name must be on her birth certificate. Successful Searching!