Phinehas Barnes was born in 1811 in Orland, Maine, and graduated from Bowdoin College in 1830. He spent several years teaching Greek and Latin at Waterville College and later engaged in various professional roles, including clerking in a bookstore and editing newspapers in Bangor and Portland. Barnes represented major companies as an attorney, notably the Grand Trunk Railway, and held positions as a trustee for the Maine General Hospital and the state agricultural college. He also served as an overseer of Bowdoin College and a director of the Portland Savings Bank. Barnes's career achievements and transitions reflect a blend of educational leadership, legal expertise, and public service.

Phinehas Barnes's political identity is marked by an intriguing blend of classical education advocacy and robust support for industrial and infrastructural growth. His career as a teacher of Greek and Latin, coupled with his representation of the Grand Trunk Railway, reveals a unique convergence of traditional values and modern economic interests. Barnes's legislative record shows an unexpected alignment with opposing factions on environmental regulations, suggesting a highly calculated approach to protecting regional industrial interests. His multifaceted professional history, from bookstore clerk to newspaper editor, underscores an ideologically agile yet deeply rooted stance in Maine's development.