Every 5 years, the US Dept. of Agriculture releases a wealth of data on the country's agricultural sector. The most recent update of the Census of Agriculture was released Feb. 4, 2009. It is based on 2007 data, and offers thousands of ways to localize reporting on what is happening in your community, and how things have changed in recent decades.
Data range from the very big picture, such as the total acreage devoted to agriculture in the country, and each state and county, to details such as the price of hogs; the number of farmers with a broadband Internet connection; the pounds of pesticides applied to selected crops; and farm ownership, by categories such as sex and race/ethnic group.