Mezue ahịrịokwu na-esonụ: Mangano gara akwụkwọ na Manual Training High School, New York Prep, na St. John's College. Ọ bụ onye òtù Phi Sigma Chi na klọb ndị ọrụ ibe ya. Na mbụ, ọ gara rụọ ọrụ n'ụlọ ebe nna ya na-eli ozu. N'afọ 1934, a họpụtara ya na New York State Assembly dị ka onye Democrats, na-anọchite anya mpaghara nke 8 nke Kings County. O jere ozi na Mgbakọ ahụ na 1935, 1936, na 1937. Ọ bụ onye nnọchi anya ọzọ na 1936 Democratic National Convention, ọ ga-abụkwa onye nnọchi anya maka 1940,
1956, 1960, na 1964 Democratic National Conventions. N'afọ 1937, a họpụtara ya dịka Sheriff nke Kings County. Ọ rụrụ ọrụ dịka Sheriff site na 1938 ruo 1941. N'afọ 1941, a họpụtara ya ka ọ bụrụ onye otu Kọmitii Democratic nke New York. N'afọ 1942, e wepụrụ ọkwa Sheriff nke Kings County wee dochie ya otu onye, onye sheriff obodo niile, na-eme ka ọ bụrụ Sheriff ikpeazụ nke Kings County.