After he took office in the middle of the Great Depression, New York City Mayor Fiorello La Guardia reshaped the city through massive public works projects (like housing, bridges, schools and hospitals) while championing immigrants and the working class. Mo Rocca talks with historian Kenneth T. Jackson about how La Guardia – a 5'2" bundle of dynamite and inveterate PR hound – changed the role that government plays in people's lives, and became the mayor that made New York great.