Big bluestem ranges across the grasslands of central and eastern North America, from Quebec and Maine west to Saskatchewan and Montana. It was a dominant grass of the tallgrass prairie, growing in low meadows, prairies, open woods, sand plains and along railways. Its fibrous roots reach 1.8 to 3 m deep, which gives it high drought tolerance, and it is adapted to fire. It shelters at least two dozen species of songbirds and feeds the caterpillars of several skippers.
Fulgenzio Vitman named the species in 1792 in honour of the French botanist Louis Gérard, which is why its Quebec French name is barbon de Gérard. Andropogon comes from Greek words meaning bearded man. Cattle eat it eagerly, and overgrazing reduced it across much of its range. It is the state grass of Illinois and Missouri and the official prairie grass of Manitoba, and it is widely sown in prairie restoration.