For the majority of 'Mericans, there is only one system. But we do call it "Imperial".
However, when you ask about feet, depending on who you talk to, you might get the question of which "feet"? US Survey foot, or International foot. They are different.
illepall
Then we could get into the Texas Vara. A unit of measurements that is exactly 1/3 of 100 feet. Talk about a pain to use, lol.
Personally, I wish we would just switch to metric. I work in a field were measurements are critical and using multiple systems causes a bunch of errors and complications.
I use Imperial in LFS. I don't like KPH because there is too many ticks per unit so to speak. A MPH analog gauge is readable, a KPH guage is hard to read.