Hired by the British during the American Revolutionary War, the "Hessians" were soldiers from which country?

Germany did not exist as a nation in the 18th century. Hesse-Hanau, Hesse-Kassel and several other German states supplied soldiers to augment the British army. George III was Duke and Elector of Hanover, hence the English-German connection at the time.

I've not been to Germany😈