Robert Armstrong served in the military during the early 19th century, gaining combat experience and being wounded in action. He held a civilian leadership role as the postmaster of Nashville, Tennessee, before taking on a military command position during the Second Seminole War. Armstrong transitioned to diplomatic service, serving as a consul in Liverpool. Later, he ventured into business ownership with the Washington Union in Washington, D.C. His diverse career trajectory showcases a blend of public service, military leadership, and entrepreneurial acumen.

Robert Armstrong's political career reflects a strategic blend of military service and public administration, suggesting a unique approach to governance shaped by both experience and regional influence. His military background, marked by significant engagements in critical battles, hints at a disciplined yet adaptable ideological stance. Armstrong's tenure as postmaster and later as a consul indicates a focus on enhancing communication and international relations, potentially at odds with more isolationist views of his time. His unsuccessful gubernatorial run and ownership of a prominent newspaper in Washington, D.C., underscore a multifaceted engagement with political and economic spheres, revealing an intricate web of influences in his policy considerations.