Captain America made his debut in 1940, just two years behind the first comic book superheroes and five years before the United States' emergence as the world's primary superpower at the end of World War II. His journey has been intertwined with America's progress throughout the decades. Known as the "Sentinel of Liberty," he has frequently provided socio-political commentary on current events as well as inspiration and warnings concerning the future.

This work explores the interconnected histories of the United States and Captain America, decade-by-decade, from the character's origins to Chris Evans' portrayal of him in the Marvel Cinematic Universe. It examines how Captain America's story provides a guide through America's tenure as a global superpower, holds a mirror up to American society, and acts as a constant reminder of what America can and should be.