Kammala jumla mai zuwa: A 1917, an zabi Greenfield zuwa wurin zama a kan Philadelphia Common Council kuma ya yi aiki har zuwa 1920. Da farko dan Republican ne, ya sauya bangarori tare da zuwan New Deal a 1933 kuma ya kasance mai goyon bayan Democrat har zuwa mutuwarsa. Ya ji daɗin dangantaka ta kusa da Shugabannin da yawa daga Herbert Hoover zuwa Lyndon Johnson. A shekara ta 1951 ya taka muhimmiyar rawa wajen kayar da injin Jam'iyyar Republican na Philadelphia. A matsayinsa na shugaban kwamitin tsara birni na Philadelphia a karkashin Magajin Gida Richardson Dilworth (1956 <unk> 58), ya kafa harsashin ginin ci gaban Society Hill a matsayin wani yanki na musamman na matsakaicin matsakaicin aji wanda zai iya jawo hankalin mazauna karkara zuwa cikin gari. Saboda ayyukansa na siyasa, a 1948 Philadelphia ta karbi bakuncin duka biyu
Jam'iyyar Republican da kuma jam'iyyar Democrat.