Why Jeans Have That 'Small' Pocket?

Pockets are a boon to men. I make it a point to have outer and inner pockets in my trousers. Same applies to my jeans. In fact, I have added several other pockets to all my jeans (My denims have pockets like cargo pants. I know it’s awkward but I like it that way).  
Jean pockets are same across genders – two in the back, two in the front. There’s a pocket, yes that odd rectangle one in the front pocket. It is mostly on the right side.

Jeans 1
The Small Pocket Is An Old Feature

Have you ever wondered why it was there in the first place? It’s been there for a long time. I tried to slide in my first cellular down that one, but it was way to small. It could be there for the nickels or the twenty dollar bills, but that space is way to cramped. Why couldn’t I use my wallet? Moreover, the coins would hurt if I folded legs or squatted down. No, it must have been there for some other purpose.
Levi’s, one of the leading American jeans brand, have the answer. Pepe’s and Wrangler gave alternate but similar explanations.

The ‘Jean-uine’ Reason For Having The Small Pocket In Jeans

This pocket was mainly introduced to hold the watches in the 1800s. In 1800s chained watches were quite popular, so people would hook these chains to the belts and keep the watches in the pockets. But wouldn’t it pinch them while sitting or folding their legs.

Jeans 2
Watch In The Pocket – The Perfect Fit

An anonymous representative from Wrangler answers the question. “Back in those days, jeans with loose flannels were quite popular. The pockets were bigger than they are today.
Back in the 1800s, cowboys used chained watches packed them in their waistcoats. To prevent them from getting lost or broken, Levi’s introduced this pocket for keeping the watch and from then it became a standard to have pockets in jeans.
Now, that’s cool, isn’t it?