Here's my trusted companion, together with some trusted companions for the other end of my body.
Speaking of baseball caps. The grandfather of the base ball cap have been a part of the bunad (traditional norwegian clothing) from where I grew up for centuries. It is called a Skjoldlue, which developed into the Østerdalslue that again developed into the base ball cap we know today.
If you look at the third picture from the top on this page:
http://www.elverumske.no/esc_norsk/draktskikk.htm , then you see the skjoldlue used typically around 1800's (and is still used to day together with the male bunad from Østerdalen.
On this page you see a variety of Østerdalslue models, which has been the prefered headwear for lumberjacks, woodsmen and craftsmen for generations in the district were I grew up. At the bottom you also see two models of the Skjoldlue:
http://www.hufa-luefabrikk.no/default.asp?menu=69
So it is really the base ball cap that has the deepest roots, and best of all, the roots are norwegian