Rudbeckia hirta is native to eastern and central North America and has naturalized widely, so it is now found in every Canadian province. In New England the typical variety is a rare native, while the common garden and roadside variety pulcherrima is considered introduced, and VASCAN's Quebec distribution for the species is computed from its varieties. It grows in fields, roadsides, open woods and clearings, and is often sown in prairie restoration and erosion-control mixes.
Linnaeus described it in 1753. The genus honours the Swedish botanist Olof Rudbeck, and hirta is Latin for hairy, for the hairs on the stems and leaves. It became Maryland's state flower in 1918. Wikipedia reports that the Ojibwe used it in poultices and infusions.