It used to be that a pocket knife was an essential item that a man carried with him. You had your wallet, your keys, and your trusty pocket knife.
http://www.artofmanliness.com/2008/0...-pocket-knife/The History of the Pocket Knife
1st Century Romans created the first folding pocket knife. They made for easy carrying for soldiers and other explorers on their journeys and conquests. However, as the use of sheathed knives became more popular, the use of pocket knives fell somewhat into disfavor.
By the late 16th Century, pocket knives began to regain popularity. They were especially popular in the American colonies. From farmers to lawyers, men from all walks of life started to carry them. The ultimate portable tool, the pocket knife was a useful aid in various tasks,