How did cars start 1940s prior ignition keys?

Answer 1

In those days, the only way to start the car is to use the "starter lever" which is a long bar with male/female head/socket fitted to it and the car engine. You insert this through a hole in front, and rotate it a few times to start the car. Very similar to kick starting a motor bike.

Self Starter was invented much later. When you had a manual starter car, and if you were to be frail and cannot start the car, then park the car in a slope somewhere near the house, and when the car starts to move, then engage the gear to "start it"