OFF: Popular headgear

[Anthony Nelson-Smith]

In spite of the comment (can't remember by whom) that wearing a baseball cap automatically reduces intelligence by 25%;  wearing it backwards, by 75%, this headgear now seems omnipresent.  However, an American acquaintance insisted that they should properly be called feedstore caps.  I can see the practical implications - giveaway caps would have the familiar adjustable strip at the rear, whereas surely part of the uniform of an established sports teams would be issued in suitable fixed sizes - but could someone in the wide range of US agrigultural experts on this list tell me if there actually is a significant difference between the two and which came first?                           Tony N-S.