A history of not using metric system.

In the 18th century, native tribes didn't use much in the way of standardized units for judging long distances. So when the Penns negotiated a treaty with the Lenape tribe, they suggested that the land they'd acquire would be "the amount one could walk in a day and a half" from a specific point.

Obviously, the Penns found the three fastest runners in the colony to later prove what that meant. They kept such a pace that two of the three collapsed on the way and could go no further.

My point?

Even in the 18th century, Americans would use anything but the metric system.