Final answer:
The dominant group in eighteenth-century Philadelphia society, in terms of wealth and political power, was merchants and traders.
Step-by-step explanation:
The dominant group in eighteenth-century Philadelphia society, in terms of wealth and political power, was merchants and traders. Philadelphia was a major northern city that had a fast-growing economy, which allowed leading merchants to form an industrial capitalist elite. These merchants came from families deeply engaged in colonial trade and had accumulated wealth through commerce.