>>714951746America doesn't use Imperial. During the Treaty of the Metre, of which the USA was one of the first to adopt, America tweaked its customary measurement system to convert between old British Units and Metric smoothly. The US was in the middle of the expansion to the western frontier, so getting everyone to adjust at that point was impossible, and the US was being considerate of all of the other countries that had yet to adopt Metric.
After waiting decades for everyone else to catch up, America stuck with its unique combined system of both measurements.
The Base 10 of Metric, as clean and useful for scientific precision it may be, is less efficient compared to the highly composite, fraction-based measurements that use things like Base 12 and Base 60 for everyday things.