[3] In 1936, Leviton built a new manufacturing plant in Greenpoint that allowed the company to begin making pull chains.

[6] During World War II and the postwar economic boom Leviton manufactured materials for the Allies.

[7][8] After the eruption of the Azores Capelinhos volcano in 1957 displaced Portuguese citizens, Harold Leviton facilitated jobs for 150 of the affected individuals who immigrated to the United States in the 1960s.

[16][17] By 2017, Leviton was considered the largest producer of electrical wiring devices in the United States, employing 6,500 people worldwide with an annual revenue of $1.5 billion.

[17] In July 2020, Leviton acquired copper and fiber cable manufacturer Berk-Tek from Nexans for $202 million.