Nope! But also kinda! All US customary units are defined by metric. That said the pound is a unit of weight not of mass. That means it’s a unit of force though we usually call that the pound force (lbf). But also since the pound is a unit of weight we generally use it as a unit of mass, but with the added qualifier of assuming it’s at the gravitational constant.

So in summary the pound is actually more closely related to the newton than the kilogram, but also its defined by the kilogram because we basically always mean pound mass.

Also I don’t think American engineers switched to metric before we stopped putting people on the moon, so yeah, in addition to doing math by hand we dealt with these insane pre renaissance units.

Also we were nearly the second country to metricate. Our second president loved the metric system and requested the French to send us metric standards but the boat sank so we didn’t switch.