John Insco Williams was a portrait and panorama painter. He was born in 1813 in Oldtown, Ohio. In 1828 he was apprenticed to a carriage painter and later worked as a professional itinerant portrait painter while traveling through central Indiana. He studied in Philadelphia from 1835 to 1840 under Russel Smith and Thomas Sully. In 1840, upon returning to Indiana, he opened a studio in Richmond. In 1841 he moved to Cincinnati and remained there for 28 years.

While visiting in Louisville, Kentucky, Williams met John Banvard from whom he learned about the painting of panoramas, and soon became an accomplished and renowned panoramist. In 1849 he painted "The Grand Moving Panorama of the Bible" which became a successful traveling reaching Cincinnati, Dayton, Baltimore, Washington, and Boston before being destroyed in a fire at Independence Hall in Philadelphia, in March 1851. Another of his panoramas, "The Great Painting of the American Rebellion", was widely exhibited and brought Williams financial security.

Williams also painted still lifes and landscapes. He married Mary Roberts Forman and had two daughters, all of which were painters. He died in 1873.