A painter of portraits and miniatures, Jacob Hart Lazarus studied with the eminent portraitist Henry Inman, in addition to attending the Academy's schools from 1841 into 1843. He appears to have spent his entire career in New York where, according to an obituary in the New York Genealogical and Biographical Record, he "painted many ideal heads and figures, rich in color and strong in design . . . . He began life as a poor boy, but became wealthy through his brush." The same account describes him as "one of the most competent judges of the value of paintings in the country . . . [whose] opinions were widely sought and recognized."
Lazarus was a regular contributor to the Academy's annual exhibitions from 1841 until 1865. His work was also shown at the Pennsylvania Academy of the Fine Arts and the Boston Athenaeum. In addition to painting portraits, he produced figure studies, genre scenes and a few history paintings. The eulogy entered into Academy minutes following his death described Lazarus as a:
frequent and popular contributor to the Exhibitions . . . in his later years . . . rarely seen among his brother Artists, but . . . kindly remembered for his many amiable traits of character.