Well, my dear the one thing you can rely in the census records is that you cannot rely on them.Sometimes they can be fairly accurate, the next time be full of errors.The enumerators took notes in the field, went home and copied them down, supposedly so they would be neater.LOL
You are right to question the 1870 family.But, they are the same one from there on back.You just need to make the tie between 1880 and 1870.Do you know when and where Mack died?A copy of his death certificate should show the names of his parents.You show family from TX to CA, did he die here in CA?Yes, I live in So. CA.
You can begin using other records to try and verify people, too.Tax and land records are a good source.Taxes meant income to the county, so they usually are fairly accurate, but I have a land record where the family name was spelled three different ways on one document.The original is given to the buyer, and the information is copied into the land record book.In the early days this was done by hand and usually by men.So, they can't blame a blond air-head making typing mistakes back then.(^_^)
My birth certificate says I'm a boy.It's been fixed --- the certificate, not me.So, you can see we some times have a challenge or two thrown in our way.
I have seen stepchildren dittoed in with the stepfather's surname.My husband has two different families where little boys were marked down as females.Names were slightly changed, too.One was Jubilee, probably called Jubie and was marked down as Julie.One was Andrew, probably called Andy and marked down as Amy.Sometimes they will give their first name, next time a nickname.Then back to first name again.Hard to make them match up, then.
Look for county histories, both the old ones and newer ones where researchers have submitted bios on their local families.
I don't know where you live, but you might check around see if there is a local genealogical society near you, or a Family History Center.You usually can get lots of help from other genealogical researchers.Most of us like to help new people get started.We were all in that same boat at one time.
If youhave any questions, let me know, I'll try to help, if I can.(^_^)