The term was originally coined to describe the group of close advisers to Franklin Delano Roosevelt during his presidency of the United Sates. He began the group when he was governor of New York State. Drawing the members from academic life the informal advisory group came to the publics attention during their developmental work on the New Deal. Members included Columbia University professors Raymond Moley, Adolf A. Berle, Jr., and expanded to include many more academicians.
The quick buildup of the program combined with a forceful personality of Roosevelt served to compensate the early oppositions. His reassuring fireside chats, broadcast to the nation over the radio,calmed and helped in explaining the issues and policies of the New deal to the American people.
It soon disintegrated as the country got back on it's feet as the economy recovered and entered World War II, but the term has remained in common usage for similar groups usually unofficially, as policy planners and advisers, especially in a government. Rexford Tugwell, who was a member of Roosevelt's brain trust, published a study in 1968.