James McDougal Hart was born on 10 May 1828, in Kilmarnock, Ayrshire, Scotland, the same township as the poet, Robert Burns. William, his older brother, would also become a landscape painter. In 1831, their parents, James and Marion (Robertson) Hart emigrated to Albany, New York. James was apprenticed to a coach-maker decorating ornamental panels, according to some authorities; to a sign and banner painter, according to other sources. He exhibited two landscapes at the Albany Gallery of Art in 1849, seven the following year. Having acquired the rudimentary skills of painting. Hart travelled in 1850 to Munich and Düsseldorf, Germany, where he studied under the landscape painter, Johann Wilhelm Schirmer, who was one of the Academy's most important teachers. While in Germany the artist made a sketching tour, for the most part on foot, along the Rhine and in the Austrian Tyrol.

Hart returned to America in 1853, opening a studio in Albany, teaching and painting there until 1857, when he moved to New York City. The artist became an associate of the National Academy of Design in 1858, academician a year later; he served on the academic council and was for a number of years vice president. He exhibited almost yearly from 1853 to 1900 at the Academy.
Often Hart would collaborate with Arthur Fitzwilliam Tait, and the two artists produced together over two dozen paintings. Tait would paint the animals, while Hart supplied the landscape. By the 1870s, however, Hart had become competent in rendering cattle, a distinctive feature of his late landscapes, their "every detail [showing] enthusiasm and earnestness, " a writer for the Art Journal noted in 1875.

In 1866 Hart married Maria Theresa Gorsuch, an amateur artist; their daughter, Letitia Bennett Hart, and son, William Gorsuch Hart, also became painters. He exhibited a landscape at the Exposition Universelle in Paris in 1867; in 1878, he contributed two paintings. His A Summer Memory of Berkshire was commended for "excellence in landscape" at the Philadelphia Centennial in 1876. Hart died of pneumonia in Brooklyn, New York, on 24 October 1901, and was buried in Greenwood Cemetery.

Kenneth W. Maddox