You'd think having spent my career in USDA I'd have a good grasp of how to navigate the USDA statistics.
You'd be wrong. Perhaps the problem is increasing senility. I prefer to believe the problem is that USDA's statistical apparatus is stuck in the middle of the last century, pre-computer.
What's most recently teed me off is dairy (see my previous post). I'm looking for a relatively simple set of figures: the historical number of dairy farms, 190xx to present; the number of cows, and total production for the same period. Then I could match trends to the New Zealand figures.
USDA has two main statistical agencies: NASS (National Agricultural Statistics Service) and ERS (Economic Research Service). In addition, if you're looking for figures on foreign ag, FAS (Foreign Agricultural Service) might come into play. If you're looking for some figures on farm programs, FSA comes into play.
Problem is I've yet to figure out how to get these figures. The NASS data seems tied to censuses. The best I've done is this ERS document
I think the basic problem is the statistical series have developed in close conjunction with users in the colleges and industry, so satisfying the needs of John Doe Public was a low priority. Back in the days of paper, before the internet, people wouldn't be coming to the agencies just to satisfy their curiosity.