Ka cika wannan magana: Daga shekara ta 1923 zuwa 1924, Phelps ya yi aiki a matsayin Mataimakin Kwamishinan Harkokin Tsoffin Sojoji na Birnin New York. Ya yi aiki a matsayin memba na Republican na Majalisar Dokokin Jihar New York daga Greenwich Village a 1924, 1925, 1926, 1927 da 1928. A shekara ta 1928, ya yi takarar takarar Majalisar Wakilan Amurka, amma ya rasa Ruth Baker Pratt, wanda zai zama dan majalisa na farko daga New York. Bayan taron Jam'iyyar Republican na shekara ta 1932, Phelps ya zama dan Democrat, kuma ya yi tafiya zuwa 1936,
1956, da kuma 1960 Democratic National Conventions a matsayin wakili. Ya sake zama memba na Majalisar Jiha (New York Co., 3rd D.) a cikin 1937 da 1938; kuma memba na Majalisar Dattijan Jihar New York (13th D.) daga 1939 zuwa 1942, yana zaune a majalisun dokokin Jihar New York na 162 da 163.