Franklin flew his kite on a Philadelphia night; He saw that lightning was electricity. Coulomb could tell that like charges repel By the inverse square of their distance. Orsted saw magnetic fields make a compass needle yield When current passed through a nearby wire.
I have a number of old science text books. Some dating as far back as the 18th century. Most of this relates to static electricity. What I found interesting was how the quantities were measured. Franklin's spark gap was used. The length of the spark was what we call voltge. The diameter of the spark was the current. To measure the current a card was placed into the gap. The spark would then burn a hole through the card.
The Ampere is one of just seven basic units of measurement. Others are the kilogram, meter, Kelvin, second, Mole, Candela. But, the ampere is used to derive many other units of measurement such as the Farad, Ohm, Henry and yes, even the volt.