Remembered widely for his pioneering work in optics and astronomy, Alvan Clark is less well known as an artist, although he is thought to have executed some 500 oil portraits and miniatures during his lifetime. Clark was born in in 1804 in Ashfield, Massachusetts, where he spent his early years on his father's farm, working at the family mill. After a brief stint in a wagon-maker's shop, he took up drawing and engraving, spending the winter season of 1824 in Boston, where he was encouraged by moderate professional success.

Returning to his home in western Massachusetts, he began itinerant work in the Connecticut River Valley as a painter of watercolor and ink portraits. By late 1825, however, he secured employment as an engraver of cylinders for printing calico patterns. For the next ten years he labored within the booming textile industry, initially in Lowell, Massachusetts, and later in Providence, Rhode Island, New York City, and Fall River, Massachusetts. During these years, Clark also studied painting, exhibiting miniatures for the first time at the National Academy of Design, New York, in 1829, and at the Boston Athenaeum in 1830. By 1836 he had ended his career as an engraver and moved to the Boston area, where he relied on miniature commissions for his livelihood. For over two decades he continued to paint portraits, increasingly in oil, maintaining a studio in Boston and a home in nearby Cambridgeport.

Concurrent with Clark's artistic development was a growing interest in science and mechanics. In 1840, for example, he patented a "false loading muzzle" for rifles, which greatly increased accuracy and diminished the time needed between shots. The turning point in his life, however, came several years later, when an increased popular interest in astronomy followed the appearance of the Great Comet of 1843. In an effort to help his older son construct a small telescope, Clark taught himself to grind and polish a glass refracting lens. Working outside of established scientific communities, he and his two sons, George Bassett and Alvan Graham Clark, gradually improved their understanding of optics and refined their technique until they became the preeminent manufacturers of telescope lenses in the world. Eventually, the firm of Alvan Clark & Sons became suppliers to all the major observatories in North America and Europe.

The painter's growing success in optics led in 1860 to a commission worth thousands of dollars for an unprecedented 18 1/2-inch lens, prompting him to close his portrait studio. He then purchased a large compound on the Charles River, building a factory and three houses for himself and his sons. Although he was renowned internationally for his work with lenses and his discoveries of new stars, it is reported that he preferred to dwell on his career as an artist, insisting that visitors to his factory also view his work in portraiture. Several years before his death in in 1887 in Cambridge, Clark finally resumed his earlier vocation, taking up his brushes again to execute several family portraits. [This is an edited version of the artist's biography published, or to be published, in the NGA Systematic Catalogue]