Opening my email on Monday morning, Nov. 17th, I found a message from CNN urgently requesting a live TV interview. I was told Barack Obama had mentioned reading a new book on FDR and the first Hundred Days the previous evening in his first major national TV interview. It was flattering that CNN assumed it was my book that he was talking about. CNN was undaunted by the fact that, as it turned out, Obama had been reading a different book, an earlier one by Jonathan Alter. Anxiety increased during the day as a high-tech CNN van tried to make it to medieval Cambridge. Eventually I stood in the driving rain on the steps of Clare College founded in 1326, telling American viewers about what their president-elect might be expected to learn from their own history.

Two weeks later British Prime Minister Gordon Brown recommended my book to readers of the Guardian newspaper as 'a classic example of how a work of history can illuminate the issues we're dealing with today.' Brown has cited Roosevelt and the New Deal as the model for his own recovery package in the UK. Media interest and requests for interview came from the US, the UK, Europe and Australia. By January 4th, the Observer (London) asserted that the book was 'Top of the political class's reading list on both sides of the Atlantic at Christmas.'

Professor Eric Foner and the late Arthur Wang could not possibly have envisaged such interest when a long time ago they asked me to write a short book for the U.S. student market on the 100 Days. I had just published a substantial overview of the 1930s, The New Deal: The Depression Years, 1933-1940. I complacently assumed that a book on the 100 Days would not be too demanding. What I had not allowed for was the fact that I did not know as much as I thought about either FDR or the 100 Days! My earlier book had concentrated on New Deal policy and how it was implemented at the local level rather than on either the motivations of the President or the legislative narrative of 1933. The 100 Days book finally came out last June and until November had attracted little attention.

What had struck me about the 100 Days?

First, how unprepared Roosevelt was to handle the banking crisis when he took office with the banks across the country closed. Walter Wyatt the holdover Federal Reserve official who drafted the legislation that re-opened the banks, remembered his astonishment that no one in the Brains Trust given 'any thought... or any real study to the problem created by this banking situation.' 'They had absolutely no plans', he recalled. But Roosevelt acted decisively to enact the measures Wyatt and other officials had previously drafted, especially for the purchase of national preferred stock - the recapitalization of the banks. Even then it was a tremendous gamble to re-open the banks on March 13 given how little the government really knew about which banks were sound and which were not. Seldom has a presidential speech been more crucial than Roosevelt's first fireside chat of March 12th. Ordinary Americans depositors were persuaded by his careful explanation that it was safer to put the money in the banks than to keep it under a mattress. If they had, instead, gone on withdrawing their money the next day, the Roosevelt New Deal would have been over before it ever started.

Henry Wallace persuaded FDR to keep Congress in session to secure the passage of farm legislation (the one policy area where the Roosevelt team had clearly worked out detailed policy proposals). Roosevelt saw the chance to launch the Civilian Conservation Corps as well and soon the momentum for the stunning legislative achievements of the 100 days was building.

Second, the economic crisis faced by FDR in 1933, three and half years into the worst Depression in American history appeared to offer huge potential for radical action, central planning of the economy, vast emergency powers for the president and the federal government. There was much talk of the need for some sort of dictatorship and Roosevelt indeed had proclaimed his willingness to seek wartime powers if Congress failed to grant him sufficient authority to act. Yet FDR had to act speedily to reopen the banks quickly, to get the economy going again, and to get money into the hands of the unemployed and the farmers. But the federal government of 1933 was a feeble instrument, which had neither the personnel nor the information to implement detailed policy or to plan the economy. Instead Roosevelt had to rely on the bankers, businessmen and farmers themselves to put his recovery programmes into action. He had to rely on the state relief administrations to work for Harry Hopkins to provide relief for the unemployed and, what is more, he had to turn to the Army to administer the Civilian Conservation Corps.

Even so Congress was not simply a passive observer. It may have waved through the legislation to reopen the banks. But farm politicians stalled passage of the Agricultural Adjustment Act. Only the threat of congressional action on a 'share-the-work' proposal forced FDR to bring forward the National Industrial Recovery Act. It was Congress, not Roosevelt, who wanted as much as $3.3 billion spent on public works and it was Congress, not Roosevelt, who wanted the federal guarantee of bank deposits.

The third thing that stood out was that the 100 Days did not possess the magic key of recovery. I do not agree with many economic historians and historians on the right, that the 100 Days hindered recovery by raising farm and industrial prices at the expense of jobs and deterring business investment through increased regulatory and labor costs. But I do believe that the AAA and the NRA and the refinancing of mortgages checked the relentless deflationary spiral whereby competitive producers cut production, prices and wages and took ever more consumer demand out of the economy. The 100 Days saved jobs in the private sector but it did not create new ones. The New Deal did not spend enough on public works in 1933 and at an early stage the idea of loans to business top invest in expansion.

Ever optimistic, Roosevelt never lost faith that he could fix on a 'one-off' recovery measure that would raise prices and bring recovery almost instantly without any need for elaborate bureaucratic programmes. Slashing government spending with the assistance of his charismatic budget director Lewis Douglas was always attractive. Going off the gold standard did not trouble him. Currency inflation and manipulating the price of gold with ingenious gold-buying schemes fascinated him. He was untroubled by the contradictions of cutting government spending at the same time as spending vast new sums on public works and relief. Although he opted for a nationalist response to the depression, (devaluation and protecting domestic price rises), he never lost the desire for a free trade international order.

FDR attracted a remarkable new generation of young Americans to Washington in 1933. Young lawyers committed to using the law as an instrument of social and economic progress, social workers, farm experts, and economists came to the capitol to staff the new emergency agencies. They were imaginative and innovative: men like James Landis and Ben Cohen who drafted the securities legislation, David Lilienthal, the scourge of the utilities in Wisconsin who would help create the TVA, John Collier, visionary reformer who came to run the Bureau of Indian Affairs, and the network of women social reformers who contributed so much to the establishment of the welfare state. The right has long derided them as impractical theorists who had never met a payroll, yet they heralded a generation in which public service was an honorable calling. They were part of the reason why three quarters of Americans as late as the 1960s still trusted the federal government to do the right thing.

When I was writing about the New Deal in the 1980s, there was still a powerful argument that the New Deal had missed the last great radical opportunity to redistribute wealth and to institute almost revolutionary, socialist change. When I was writing this new book, the most powerful current arguments against the New Deal came from the right: that the New Deal was the decisive wrong term in the twentieth century. The New Deal produced the Big Bang of the Federal Government, delayed recovery, was anti business, promoted class warfare, not class unity, and destroyed American traditions of voluntarism, self-help and individualism. This free-market critique looks unconvincing in 2009. To my mind what is striking about the 100 Days in 1933 is there were neither the plans nor the opportunity for a huge power grab by the Federal government. But government intervention in 1933 and after - especially relief for the unemployed and the re-financing of farm and home mortgages - demonstrated that a government need not be paralyzed in the face of economic catastrophe. This aid to ordinary Americans promoted social cohesion at a time when a failure to act would have unleashed massive social turmoil and anti-democratic forces.

What can the intellectually gifted President Obama, himself a gifted communicator like FDR, learn from the 100 Days?

That there is no alternative to bailing out bankers and the major industries, however much it rankles. But that assistance has to be balanced by appropriate regulation and assistance to the unemployed and threatened homeowners. To create new jobs in the private sector a lot of money has to be spent, probably more than it is comfortable to contemplate. Infrastructure investment works -- as the New Deal's public works programs showed. A President, even in crisis situations, cannot simply dictate to Congress. Obama will have to work with Congress on the nuts and bolts of legislation and to do so at a time when congressmen will not hear the same powerful messages from their constituents to back the president at all costs that they heard in the even more desperate economic situation of 1933.

My students in Cambridge, England, as in the United States and as in the rest of the world have huge expectations of the new President. Even more than in 1933 what the President of the United States does or does not do will have a huge impact on the world they live in. They and I will watch his first 100 Days with intense interest.