The United States does not use "Imperial" units. We use some Customary Units that are defined in terms of SI units and share names with some Imperial units.
The point is that saying "The United States uses Imperial Units" is, generously, ignorant.
yes - for example a US fluid Oz is different from everywhere else, as is a cup, a pint, a Venti (twenty what?) and many of the units used in cooking - using American recipes without translation can produce crap - Imperial fluid ounces are totally different largely due tax politics of the 1700/1800s
The point is that saying "The United States uses Imperial Units" is, generously, ignorant.