Can an american citizen these days, travel throughout the USA without a passport?

I do it all the time.

I was stopped from Los Angeles to Las Vegas, and the Nevada boarder patrol asked me for my passport.

you only need a passport for other countries

An American citizen doesn't need a passport to travel anywhere in the US. Only when you cross international borders, not state borders.

yes... i've been throughout the east coast and the central united states and i've never posessed any sort of passport.

passport is only required when entering and leaving the USofA,not from State to state. We are free to move about the country.

absolutely - unless you're 1500 miles from any port of entry dressed in some ethnic garb and don't speak a word of English while you're taking pics of a nuke plant.

nope, one isnt needed :)

We have never been required to have a passport here in the USA. We are required to have a form of identification on our person, as we travel.