Final answer:
The German soldiers who assisted the British during the American Revolutionary War were known as Hessians; these mercenaries from German principalities were a key military force deployed to suppress the rebellion.
Step-by-step explanation:
The German soldiers who served as auxiliaries to the British Army during the American Revolutionary War were known as Hessians. These mercenaries were hired by Great Britain to help suppress the American rebellion. They were professional soldiers from the German states of Hesse-Cassel and other principalities and played a significant role in many battles during the war. Although they were known for their discipline and military prowess, the use of foreign mercenaries was a point of contention and contributed to American resentment against British policies.