On leaving Princes Edward Holden went to work at the family firm of Holden and Frost, makers of horse-drawn vehicles and fittings.
With the advent of the motor car, Edward Holden played a crucial role in the company commencing body building in 1917. Through the introduction of innovative work practices, which increased production, Holden’s Adelaide assembly line was the largest outside of the USA by 1929. In 1931 Holden amalgamated with General Motors and Edward Holden became chairman of the new company. Sadly, Holden did not live to see the launch of Australia’s first mass-produced car (the Holden) in 1948.
He was also active in politics at State level as a Legislative Councillor from 1935 to 1947. Edward Holden was knighted in 1945.