Steele became a leader of the Hoosier Group. This circle of painters defined American Impressionism in the Midwest. His approach shifted from studio-bound portraiture to plein air painting. He focused on the seasonal changes of Indiana. He captured the effects of mist and sunlight. Paintings such as Morning by the Stream and June Glory demonstrate his ability to translate atmospheric conditions into colour. He preferred to work directly from nature in the hills of Brown County.

Modern collectors value Steele for his honest portrayal of regional terrain. His paintings provide a record of the rural American environment before industrial expansion. Paintings like The Ohio River from the College Campus, Hanover or House of the Singing Winds offer a sense of place. These paintings suit contemporary interiors. They combine technical skill with a calm, observational quality. His studies of snow and light remain popular for their clarity.