U.S.A. had what is called the Malaise Era. "G.M." took it quite hard and made some really bad stuff and bad management decisions - including that downsized "Cadillac" - seen one pun : "Here is your ´´Cadillac´´. "No sir, I think that's my ˝Buick˝".
"Ford" took it better, trough all that in the late '80's made some very modern looking cars, but with really bad transmisions.
Dont' know too much about "Chrylser" Corporation a.k.a "Mopar".
In the '90's, there where some good cars, some bad ones.
But even before the crisis of the 2009, U.S..A. made cars wheren't the dream that they used to be and the source of inspiration that they used to be. "Lincoln" made some nice models in the early '000's, "Cadillac" camed with that ugly 'Escalade', but... no more of that power of American cars. O.k., the Europeanens and the Japanese made some good cars, some not good, but which still had the looks, but I don't think this is the only reasons that caused the decay of U.S.A. auto manufacturers.