Melania went for a more classic look for the event, which marks 100 years since the ratification of the 19th Amendment, which granted women the right to vote.
The Slovenian-born First Lady was dressed in a sharp white designer suit by American fashion designer Michael Kors.
The slim fitting suit retails for around £1700 ($ 2,195) and features a modern blazer with an asymmetric hem.
The sleek jacket was paired with a white knee-length pencil skirt, but Melania also accessorised the look to give it an update.
Melania chose to dress all in white for the occasion, joining some of the other guests in a special nod to the suffragette movement.
White is historically the colour associated with the women’s suffrage movement.
But aside from the gingham extras, Melania kept the rest of her look simple, with her trademark highlighted hair blow-dried into soft tousles, while for her makeup she kept to her signature smokey eye.
Photos from the event were posted on the FLOTUS Instagram account.
The caption read: “100 years ago today, the #19thAmendment was ratified, securing the right to vote for American women.
She stepped off the plane wearing a camel-coloured shirt dress by British designer Stella McCartney.
The dress is no longer on sale but was thought to be worth over £500, though it wasn’t the most expensive part of her outfit.
Melania also carried one of her exclusive Birkin handbags, which can cost from £14,000 a piece.
The First Lady made headlines for appearing to shun her husband’s hand as she walked down the steps, clutching her bag to her body – though it may also have been a bid to keep her full skirted dress from blowing in the wind.