America can be explained by our choice of 60 Hz electricity. 🇺🇸

When the frequency increases, the copper and steel consumptions of the generator and transformer decrease, along with the reduction of weight and cost, but will make the inductances of the electrical equipment and transmission line increase, reduce the capacitances and increase losses, thereby reducing the transmission efficiency. If the frequency is too low, the electrical equipment’s materials will increase, along with heavy and high cost, and will make lights flashing obviously. Practices have proved using 50 Hz and 60 Hz frequencies are appropriate.