Anna Mary Robertson Moses (1860-1961) was probably America's best-known primitive painter.

Anna Mary Robertson was born in Greenwich, N.Y., on Sept. 7, 1860, one of 10 children of a farmer. At 12 she began earning her living as a hired girl. In 1887 she married a farm worker, Thomas S. Moses, and the couple settled on a farm in Virginia. They had 10 children, 5 of whom died at birth. In 1907 the family moved to Eagle Bridge, N.Y., where Grandma Moses spent the rest of her life. She died on Dec. 13, 1961.

While living on the farm, Grandma Moses had embroidered pictures in yarn. At the age of 76, because of arthritis, she gave up embroidery and began to paint. Her early work was usually based on scenes she found in illustrated books and on Currier and lves prints. Her first one-woman show was held in New York City in 1940 and immediately catapulted her to...