Despite the similarities, these dress styles are different
Imperial Size
From a simple shift dress which helped democratize womens fashion to a bold political statement, it has moved through various iterations which reflect changing ideals of beauty and body image. Many black dresses existed before Chanels 1926 design, and black was already a fashionable color, Ripley notes
3D floral lace appliqus glitter with subtle beading all along the entire fit and flare silhouette of this wedding dress, making a unique statement
Here is what Emily Post says about attire for black tie formal wear: Women Formal (floor length) evening gown Dressy cocktail dress Your dressiest little black dress Men Black tuxedo jacket and matching trousers Formal (piqu or pleated front) white shirt Shirt studs and cuff links Black bow tie (silk, satin, or twill) Black cummerbund to match tie, or a vest Dressy braces to ensure a good fit (optional) No gloves Black patent shoes and black dress socks In summer, in the tropics, or on a cruise: White dinner jacket, black tuxedo trousers plus other black tie wardrobe You can find their full guide to attire, from Casual to White Tie, on their website