Ignition key invented in 1949?

The Irish forensic examiner says in episode 1 that "the ignition key wasn't invented until 1949 in America". Is that actually true?

Did cars before that not have a key to prevent the engine being started? I know it was common practice, especially during WWII, for drivers to immobilise a vehicle by removing the rotor arm from the distributor, but I always thought that this was *in addition* to the security provided by a key, possibly because keys were easier to duplicate and because there was the risk of bypassing the ignition switch with a hot wire.

Earlier cars (eg Morris Minor) had a separate starter button which just operated the starter motor, but surely even separate-starter cars still needed a key to turn on power to the spark plugs (via low-tension, distributor and coil).

I wonder if what was invented in 1949 was the combination of the key and the starter-motor, doing away with a separate starter button - which was an irrelevant change when it comes to dating a key.

(As a matter of interest, why did cars start to be supplied with a single key that operated ignition, doors and boot, as opposed to two keys, one for ignition and the other for doors/boot? I remember cars in the 1970s had separate keys but some time around 1980 all manufacturers more or less simultaneously changed over to a single key. I wonder what triggered the change?)