Did Robert Millikan's results impact on determining the charge of an electron?
Millikan cleverly devized a means to measure electronic charge......
The oil drop experiment is famous, and provided a means to measure electronic charge. Millikan and his students must have been consummate experimentalists, and he was able to show that the electric charge of oil-drop were all small integer multiples of a certain base value, i.e.
Unfortunately, a negative charge had been assigned to the electron. It would have been more convenient for chemists had the electron been designated a positive charge, and the nuclear charge as a negative quantity. This would have helped generations of quantum chemists (and quantum physicists).