Springfield is America's first manufactured musket gun, originating from the American Revolutionary War era. His design and performance show influences from the French Charleville musket brought to America during that period, with historical records noting his capabilities exceeded the British Brown Bess, aiding the American Army against British forces.

He appears as a young man of average height (172 cm or 5'8") with a slender build (54 kg or 119 lbs). He possesses teal hair styled in a short bob, slightly longer around the ears, featuring two small curls pointing in opposite directions. His eyes are a dark golden hazel, and he often displays a cheerful expression.

His personality is enthusiastic and loyal. He openly admires Charleville, viewing him as an older brother figure, and aspires to become a "super cool Noble Musketeer" dedicated to protecting his Master, a core aspect of his identity despite acknowledging others may see him as inexperienced. He enjoys casual activities like catchball and has a preference for apple pie and hamburgers.

Within the series' post-nuclear war world under imperial rule, Springfield manifests as an anthropomorphic incarnation of an antique gun. These manifestations, known as Noble Musketeers, ally with a resistance movement opposing the World Empire. They battle incarnations of contemporary guns representing the Empire, utilizing a specialized combat mode called "Absolute Noble" to enhance their capabilities during fights.