Yesterday I introduced myself and my short version of the story of how I think the term "fitness" in our (USA) culture has become narrow and distorted beginning sometime between the late 1940's and mid 1950's. This was not a midnight awakening that turned my view point around, but rather a gradual education. A great resource that can better frame the basis for my thought is oldtimestrongman.com . A massive collection of material that gives time stamps to concepts of fitness in our culture. You can follow along and read from a multitude of references and compare to our own thoughts and definitions of health and fitness. Another huge reference list can also be found on The Golden Age of Iron Men. Together these two resources house thousands of pages of history and a good start to understanding where it all started.
Currently the Manual of Physical Training. US ARMY 1914. is my template for a working definition of fitness.
I encourage you to define yours.