Dear Lord. The average standard of living has increased multi-fold since the glorious days of our founding. The relative share, and plight of the poor, has meanwhile decreased significantly, while a social safety net now exists to protect those at the greatest margins of society. Workers now have rights, and protections, decent working hours, living wages, etc. which they didn't have before, making it harder (though not possible) for owners of capital to exploit them (which is their natural inclination). In the process, civil liberties/rights have been extended to nearly all citizens (still working on this one). Women, blacks, other ethnic groups, gays, etc. now have opportunities for economic, social, recreational, etc. activities that would have been unimaginable even 40 years ago. Average life expectancy has risen dramatically, and most Americans have at least some access to a world class healthcare system (still working on this one too). I could go on.
In short, American citizens as a whole are so much better off economically and socially, have greater freedoms and protections against the capriciousness of life and the market system, than even as recently as the mid-20th Century, and incredibly more so than the halcyon days of the glorious founding, or the mythical wonder years (a al 50's) that the social conservatives swoon for, that I find such arguments as yours to be totally detached from any semblance of historical perspective or actual on the ground reality.
Yes it's far from perfect, but it's so much better than it ever was before, such false nostalgia for the 'good old days' notwithstanding.