Is the standard of living of poor & middle class people higher than in the past? I really hope this is not opinion based.  I am just looking for numbers, links, straightforward proof if possible that the lifetime we are in now, this decade, most of us are living better than in the past since the cost of living has increased and so has income inequality.

Are more people on welfare than any time in history for instance?
I think you are looking for data on real median incomes. If this concept is unknown to you, you can read about it on wikipedia.

According to the data the real income of most households decreased after the financial crisis but is still above the 1995 level. This means that most households do live better.

I don't know if the number of people on welfare would be a good indicator of economic prosperity as there have been some changes in the US welfare system recently, drastically reducing the number of recipients.