The confusion comes from naming American units "imperial" - after British, and having international - metric - system created by the French revolution, with "liberte" an important goal. So it could be argued that it's actually SI which has freedom units. On the other hands, Americans are quite often characterized as freedom "distributors"...
Most Americans that I have pointed this out to look at me in disbelief. The vast majority have never heard of US Customary Units. Whenever they refer to their system of measure they say imperial, and many are unaware that volume measure in the Imperial system is different from US Customary. I fought again the use of imperial as the name for the system for over twenty years in a multinational company to no avail.
Send them this handbook from NIST! :) Section 2 covers all of the customary measurements, some with names hardly anyone knows (Apothecaries Units? Gunter's Chain Units?)
I've never met a Canadian who gave their height or weight in metric units.
Or a recipe in Canada that doesn't set a temperature Fahrenheit. Also: the size of TVs and screens. Or paper.
News articles in particular tend to go out of their way to use strange units of measurement. Bananas, fishes, football fields, car lengths, swimming pools... Anything but SI system of units. Even the feet gallon pound values are rare finds that need perseverance.
Eagle wingspans isn't something I've seen used, but the football fields unit does make sense when talking about something which is relatively long (can be measured in 1/2 to 3x the length of such a field).
If you tell the average (US) person 1000 feet, they won't be able to envision it. But if you say "a little more than three football fields", they can visualize that.
The point of strange units of measure is just to make a quantity relatable.
> Chairman of the Committee on House Administration, Bob Ney, renamed the menu item in three Congressional cafeterias. The political renaming occurred in context of France's opposition to the proposed invasion of Iraq
"Refuse to go to war with us? We'll... remove you from our cafeteria menu! Take that!"
The country that landed men on the moon adopted the metric systems as the basis of its measures before most other countries and programmed its moon landing systems using metric.
The country is a metric country (see: Official definition of the US foot).
Its citizens, however, largely still roll coal measured by chains to the hogshead.
The previous moon thing is a joke and at least partially an explanation for "freedom units," which is a joking (I think) commentary about the citizenry's beliefs about "their freedoms," and somehow these freedoms translates to freedom from using the metric system when they roll coal along a couple furlongs of interstate (in a truck that contains only metric fasteners.)
It always amuses me when I watch a machining video from someone using metric. I've just been exposed to too many US machinists and am much more familiar with "thous" and "tenths" but baffled by microns and 0.02mms.