Following his resignation from the army, Burnside became an executive in the railroad industry, demonstrating his continued business acumen.

Burnside successfully ran for Governor of Rhode Island and was elected to the first of three consecutive one-year terms.

During his time as governor, Burnside focused on promoting economic development, improving infrastructure, and supporting education. He was a popular governor, known for his charisma and commitment to the state.

Burnside was elected to the United States Senate, representing Rhode Island. He served in the Senate until his death in 1881.

As a Senator, Burnside focused on military affairs, veterans' issues, and economic development. He was a respected member of the Senate, known for his moderation and commitment to national unity. Served as chairman of the Committee on Military Affairs.