In Oleg Cassini's 1987 autobio---In My Own Fashion---he writes Jackie wanted to wear the gown he designed for the Inaugural Ball held the evening of the inauguration, but that she had already ordered a custom-made gown from Bendel's and could not back out of the order. She did wear Cassini's magnificent gown-----to a ball held the night before.
Later she wanted the Cassini gown in the Smithsonian collection of First Lady inagural ball gowns--she loved it so much. But they insisted she submit the Bendel gown since it was the one she wore. In several Jackie bios she is shown in the Bendel gown
This is Jackie in the Bendel. She wore a cape over it for the ball.
BERGDORF INAUGURAL BALL GOWN
CASSINI NIGHT BEFORE INAUGURAL BALL GOWN
