Story highlights FDR was the first president measured against 100 days

It's a yardstick still used

Washington (CNN) The first 100 days of a two-term presidency amount to about 3% of an eight-year span, but for decades the opening stretch of an administration has become the barometer of a commander in chief's governing power, or lack thereof.

The measurement began after Franklin Delano Roosevelt entered office amid the tumult of the Great Depression. With banks caving in and jobs vanishing, FDR set to work passing laws and establishing new government bureaus to curb the economic suffering.

He swore in his entire Cabinet at once, signed 76 bills into law, and began rolling out the New Deal in his first 100 days in office -- a frenzy of activity that, ever since, all presidents have been matched against.

Presidents usually chafe at the comparison to FDR, who benefited from a Congress that could hardly say no at a time of economic calamity. But the 100-day construct abides, fueled both by journalists eager for a yardstick to measure a new administration and by presidents themselves, who lay out 100-day plans as candidates and almost unfailingly fall short.

On Saturday, President Donald Trump reaches his 100-day mark with a mix of anxiety and dismissal. He embraced the concept during his campaign, spelling out a plan for the opening stretch of his presidency that included repealing and replacing the Affordable Care Act, funding the construction of a border wall and passing a $1 trillion infrastructure measure.

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