Government report on ... coffee cans?
Why does the Bureau of Land Management care about what coffee cans looked like in the 1910s? For a very good reason. According to the document's introduction, Hill's Brothers Coffee cans are a great way to date digs dating back to the late 1800s because of the tendency of Hills Brothers to change their can designs every so often.
You can read the 39-page PDF document here.Download file
Hills Bros. coffee can chronology : field guide, published by U.S. Dept. of the Interior, Bureau of Land Management in 2006.
Source: Free Government Information Blog