The American copper is a small butterfly with a wingspan of about one inch. The upperside of the forewing is orange-red with black marks and a brown-black border. The upperside of the hindwing is brown-black with an orange border containing black indentations. The underside of the forewing is orange, with a gray edge and black marks. The underside of the hindwing is gray with some black spots and a red-orange line paralleling the wing edge. The larva is green with scattered, short hairs that may appear rust or pink.
The American copper is found where its larval host plants, sour dock (Rumex acetosella) and curly dock (Rumex crispus), grow. Both of these plant species are native to Europe and are present throughout Illinois. The American copper is active from mid-spring through October. Multiple generations are produced each year. It overwinters in the larval or pupal stage. Adults feed on nectar. It is possible that this species came to America with early settlers from Europe in shipments of hay and is not native to the eastern part of the United States.