Why does America use 110V 60Hz?

Why is 60Hz frequency used in America instead of the 50Hz used in most of the world? The use of 50 versus 60 Hz is purely due to historical reasons, with companies in the US making 60 Hz equipment and those in Europe making 50Hz equipment so that they have a monopoly . This rivalry led to the split you see today.

European countries use 50Hz They decided to use 50Hz instead of 60Hz, because they use a decimal (US using duodecimal), this calculation is more convenient, but they still retained the voltage of 110V. Unfortunately, 50Hz AC efficiency is far poorer than 60Hz.

North America and Japan use 110V/60Hz electricity where as rest of the world use 220V/50Hz. The reason was historical. Engineers in USA originally laid lines for 110 V where as in Europe they did with 220 V. After that, it would have been too expensive to change the system .