The sitters are the four sons of the hide and leather merchant Shepherd Knapp (1795–1875) and his wife, Catherine Louisa Kumbel (1793–1872). They are, from left to right, Gideon Lee (1821–1875), Shepherd Fordyce (1832–1886), William Kumbel (1827–1877), and Peter Kumbel (1825–1871). Shepherd Fordyce Knapp appears to be no older than two, which would date the work to 1833 or 1834. All of the children would marry and Gideon Lee Knapp would later become the owner and manager of the Green Point Ferry. The portrait type, among the most complex and successful painted by Waldo and Jewett, is one informed by eighteenth-century English portraiture. Waldo studied in London between 1806 and 1809 and his exposure to portraits by Benjamin West, in whose studio he was an assistant, is evident.
