Why Marmalade and not jam??

From:  "Rocky"

why is marmalade called what it is - not orange jam or citrus jam?

TB went on a search looking for the answer and came back with this: 

Marmalade is a jellylike preserve made from the PULP and RIND of fruits, especially citrus fruits. Jelly is a liquid containing pectin or gelatin or by the addition of gelatin to a liquid, especially such a substance made of fruit juice containing pectin boiled with sugar. Jam is a preserve made from whole fruit boiled to a pulp with sugar.

Jamalique gave us this simple thought: 

They call it marmalade and not jam because it sounds cooler. Duh.