The slate-blue crepe dress worn in 1933 by Eleanor Roosevelt at her husband’s inauguration ball and Michelle Obama’s white silk chiffon gown are among treasures on display at a new first ladies’ exhibit in Washington.

The ball gowns were also used to serve the nation

The National Museum of American History is organising an exhibit of 26 dresses and over 160 artefacts including portraits and silverware that belonged to US first ladies that will refresh a longstanding section of the museum.

The highlight, however, is the inaugural ballgowns, such as a strapless lace number worn by Julia Grant (wife of Ulysses Grant) in 1869, the all burgundy velvet chosen by Caroline Harrison (wife of Benjamin Harrison) in 1889 and Nancy Reagan’s white satin and lace from 1981.

“It’s their debut, this is the dress of record, and the one which stays in people’s memory,” said Lisa Kathleen Graddy, the exhibit’s curator, noting that it is a century-old custom for the dresses to enter the museum.

First ladies are “on the public stage all the time and want to look appropriate because they represent the nation,” she added.

The term “first lady” is not official – the first Presidential spouse was known as Lady Washington and the term did not come into use until Dolly Madison, wife of James Madison, was buried in 1849. For the inaugural ball, first ladies got a chance to make their statement through their dresses, according to Ms Graddy.

Also on display is Barbara Bush’s blue velvet and satin dress from the inauguration ball in 1989 and the violet lace chosen by Hillary Clinton four years later.

But the display includes other dresses, such as the pale yellow silk evening gown that Jackie Kennedy wore in 1961 to the first state dinner hosted by JFK.

The ball gowns were also used to serve the nation. Lou Hoover (Herbert Hoover’s wife), renowned for her elegance, was the first President’s wife to be pictured in Vogue, and in 1929 she wore a cotton evening dress to promote the US textiles industry.

But not every first lady was as patriotic when it came to fashion.

Frances Cleveland (wife of Grover Cleveland) in 1895 bought a Jacques Doucet dress in Paris, while Edith Wilson (Woodrow Wilson’s spouse) in the 1920s favoured black robes from Worth, another French fashion house.