Chester de Hart’s surname was spelled a couple of different ways; I’ll keep it simple by using his daughter’s version.
Chester de Hart (1883-1912) was an civil draughtsman by trade and born in New York. He was the second son of Henry Garrett Voorhees de Hart (1849-1917), a physician, and Margaret Adellaide Winship (1850-1909). He married Minna “Minnie” Sievert in 1906. Chester’s and Minnie’s only child was Elaine de Hart (1909-1993) who married Harry Helgans (1894-1965) in 1934. There were no grandchildren.