Yes, more than seven out of every one hundred total visits to any website in the US is now to Facebook. Google, you are number two.
Facebook is a massive social behemoth around the world, but in its home market it has shown particular strength. The website has now grown past its former status as a household name to being the location of a generation. Its traffic numbers reflect this. The graph speaks for itself, so we will let you read it:
Data from Hitwise, via TechCrunch.