 Dalzell was a financial analyst for the National Broadcasting Company in New York from 1965 to 1966, and was a visiting lecturer in law at Wharton from 1969 to 1970.From 1970 to 1991, Dalzell was a lawyer in private practice in Philadelphia at the law firm Drinker, Biddle & Reath.In 1971 he served as treasurer for the unsuccessful mayoral campaign of longtime friend W. Thatcher Longstreth, and later was involved in the controversy concerning Philadelphia's Home Rule Charter, which mayor Frank Rizzo sought (unsuccessfully) to amend to allow him to seek an additional term in office.