* Granville Woods: railway air brakes that provided the first safe method of stopping trains (1903) and the third rail to power underground trains (1893)

* Garrett A Morgan: gas mask used in World War I (1914) and traffic lights (1923)

* Dr Charles Drew: set up blood banks all over the world (1940)

* Frederick Jones: refrigeration for transport trucks (1938) and railroad cars (1945)

* Richard Spikes: automatic gear shift (1932), automatic shoe shine machine (1939), multiple barrel machine gun (1940), horizontally swinging barber chair (1950)