I'd say America is just as free today as it was 8 years ago.
Yes, some rights have been infringed upon - mostly property rights (i.e., Dakota oil pipeline), but it seems the people most infringed on there are fighting back and just may win.
If you want to claim that the tax penalty in PPACA (bka, ObamaCare) is a form of infringing on one's property rights (i.e., confiscation of money), okay...I'll grant you some leeway there, but not much since few Americans are grossly impacted by the law.
You could try to claim that privacy rights have been infringed on except, the Supreme Court ruled that searching an individual's cellphone during a routine traffic stop is a protect right and the Patriot Act put the brakes on the secret surveillance program Edward Snowden brought to light.
As far as I'm concerned, our nation isn't at that "slippery slope" inflection point that seem to make up many hyperbolic claims. It's great that you're so concerned about it, but I'm afraid we ain't quite there yet. The moment martial law is declared which is different from a curfew during a natural disaster or some crisis of the moment, I'll take your far more seriously on these such matters. Until then...
eace