Walter Harriman began his career as a teacher before transitioning into politics as a Democrat. He served in various state legislative roles and held the position of state treasurer. His military service during the Civil War included commanding the 11th New Hampshire Infantry and later a brigade in the Army of the Potomac. Post-war, Harriman shifted to the Republican Party and was elected Governor of New Hampshire, where he focused on economic development and education reform. He also authored historical and travel works, reflecting his broad intellectual interests.

Walter Harriman's political identity is marked by an intriguing blend of regional economic advocacy and educational reform, framed within a unique ideological journey from Democrat to Republican. His legislative focus on developing New Hampshire's agricultural and industrial sectors while simultaneously investing in education reveals a calculated approach to regional development. Harriman's military leadership during the Civil War, coupled with his post-war political shifts, showcases an ideologically agile stance that balances regional interests with broader national considerations.