In this painting, you see a woman nursing her baby uncovered in mixed company. She is sitting on the left side of the painting near the wagon. Her dress is unbuttoned, exposing the breast. While this painting is not necessarily a snapshot of breastfeeding norms in the mid-1800s, it does reveal cultural attitudes towards nursing in public around the turn of the 20th century.
I wish I had a better quality image of the mother & child. If anyone had access to it, please send it my way.