Overview
Captain America's shield is a fictional item appearing in American comic books published by Marvel Comics. It is the primary defensive and offensive piece of equipment used by Captain America, and is intended to be an emblem of American culture.
Over the years, Captain America has used several shields of varying composition and design. His original heater shield first appeared in Captain America Comics #1 (March 1941), published by Marvel's 1940s predecessor, Timely Comics. The circular shield best associated with the character debuted in the next issue, Captain America Comics #2.
Original shield
In his debut, Captain America (secretly U.S. Army Private Steve Rogers) is equipped with a heater-style shield made from steel. After complaints by rival comic-book publisher MLJ that the design was too similar to that of its own patriotic hero the Shield, Timely Comics replaced the triangular shield with a disc-shaped one.
From Wikipedia (CC BY-SA 4.0).
