Final answer:
The largest indigenous group in Atlantic Canada at the beginning of the eighteenth century was the Mi'kmaq, part of the Algonquin-speaking Wabanaki Confederacy.
Step-by-step explanation:
At the dawn of the eighteenth century, the largest indigenous group in Atlantic Canada was the Mi'kmaq. The Mi'kmaq are part of the larger Algonquin-speaking Wabanaki Confederacy which had been in conflict with the Iroquois Confederacy over regional control and economic and political dominance.
European settlers signed treaties with indigenous groups which covered various rights and trade relations, including the lucrative fur trade. Confederacies like the Mi'kmaq were made up of culturally and linguistically related groups with a shared political affiliation, vital in the dynamics of alliances and conflicts at the time.