Her brother , Thomas D'Alesandro III , also was Mayor of Baltimore . Pelosi is Italian-American and was born Nancy Patricia D'Alesandro in Baltimore , Maryland , the youngest of six children of Anunciata M. ( `` Nancy '' ) and Thomas D'Alesandro , Jr. , who was a Democratic party U.S. Congressman from Maryland and a Mayor of Baltimore . Pelosi 's brother , Thomas D'Alesandro III , also a Democrat , was mayor of Baltimore from 1967 to 1971 , when he declined to run for a second term .