Most American academics work for the federal agencies at some level. Whether they admit it or not. All state schools are well "state" schools. Their autonomy is regulated usually by the legislature of the state and a board or regents/governors.

Even more importantly in the United States the principle and primary funding agency is the National Science Foundation (NSF). NSF is a competitive federally funded program. With major notable exceptions like Lilly, Macarthur, Carnegie, etc. few if any private agencies fund academics who aren't working for them directly.

Almost all of my external funding is from NSF, NSA, DOD, DOJ, NIJ and really few of my funding dollars are from NSF directly. I do have a tidy no strings attached grand from CISCO for $120K but they were just being nice to me when I started my laboratory.

Personally I've been on a grant seeking/funding hiatus (not a good choice professionally but rewarding personally) as getting the PhD (75% funded by my University, 24% funded by NSA/DOD, 1% by me) is more important for my goals as University faculty.

It is interesting that a doctorate is not required for tenure but funding is required. My choice (knowingly putting myself at risk for continued employment) was to get the doctorate. The drive in academia for funding is something called salary savings. You buy back your salary and are given "release" time to do "research" and they fill the "release" time up with committee assignments and grunt work.

I really enjoy research and as I learn more about my field of study my research questions get more and more interesting. I don't really know what those social science, history, anthropologists do for research. All I need is a bunch of computers and some victims (I mean students) to get my research done.