She was the eldest of three children of the Hudson River School painter James McDougal Hart[2] and the artist Mary Theresa Gorsuch Hart (d. 1921), who was best known for Easter Morning, a widely reproduced image of a white marble cross draped in flowers.

(Her brother Robert Gorsuch Hart, a water-plant engineer, died while working in Mexico in 1906, at age 37.)

Starting around 1885, Letitia Hart exhibited her work at venues including the American Water Color Society, Art Club of Philadelphia, Brooklyn Art Association, James Gill's gallery in Springfield, Mass., Louisiana Purchase Exposition, National Academy of Design (she received the Norman W. Dodge $300 prize there in 1898 for best painting by a woman),[5] Pan-American Exposition, Union League Club of Brooklyn, and the Woman's Building at the 1893 World's Columbian Exposition in Chicago, Illinois.

[4] With her sister (who often posed for portraits) and father, she commuted from Brooklyn to a top-floor studio at 11 East 14th Street in Manhattan.

Correspondence from her survives at the Archives of American Art (Charles M. Kurtz papers, Carnegie Institute records).