Ted Kennedy was born in Brookline , Massachusetts , which is a neighborhood in Boston . He was the youngest son of Joseph P. Kennedy Sr. and Rose Fitzgerald Kennedy . Kennedy was born in St. Margaret 's Hospital on February 22 , 1932 in the Dorchester section of Boston , Massachusetts , the youngest of nine children of Rose Fitzgerald and Joseph P. Kennedy , Sr. , who were members of prominent Irish-American families in Boston and who constituted one of the wealthiest families in the nation .