Thomas Swann attended prestigious institutions, including Columbian College and the University of Virginia, and studied law under his father's tutelage. He began his career in public service, securing an appointment with the United States Commission to Naples and subsequently serving on the Alexandria City council. Swann transitioned to a prominent role in the railroad industry, becoming a lawyer for the Baltimore and Ohio Railroad and later its president. His leadership extended to state governance, serving as Governor of Maryland and representing the state in Congress, where he chaired the Committee on Foreign Affairs.

Thomas Swann's political identity is marked by a unique blend of conservatism and pragmatism in Reconstruction-era governance. He opposed Radical Republican policies, showing a preference for President Andrew Johnson's lenient approach. Swann's advocacy for infrastructure improvements and immigration reveals a forward-thinking yet selective approach to post-war state governance. His role in the Committee on Foreign Affairs suggests a strategic focus on international diplomacy, balancing regional interests with broader national concerns.