The electric was introduced in the United States back in the 19th century and that’s more or less where it has stayed since. It was the most commonly used execution method until lethal injection took over that distinction toward the end of the 1900s and into the 2000s (via Britannica). There was a sharp decline in the number of instances in which the electric chair was used after the 1972 moratorium on the death penalty put in place by the Supreme Court which lasted until 1976, per the National Constitution Center. However, between 1890 and 1972, electrocution was the method used in 4,251 executions. From 1976 to the present day, it has only been used 160 times.
States where the death penalty is still active sometimes offer prisoners the choice of being executed by either electrocution or lethal injection, while Nebraska was the last state to only use electrocution. Outside the United States, the electric chair is rare and isn’t used even by countries that carry out the most executions — which according to the BBC included China, Iran, Saudi Arabia, Iraq, and Egypt as the top five in 2019, with the United States in sixth. However, the Philippines used the electric chair until 1976.