"Statue of Freedom does not wear or hold a knitted liberty cap, as would have been expected in nineteenth-century art. The knit cap provided to freed slaves in ancient Rome had been adopted as the symbol of liberty or freedom during the American and French Revolutions and was usually shown as red.

The Statue of Freedom's crested helmet and sword, suggesting she is prepared to protect the nation, are more commonly associated with Minerva or Bellona, Roman goddesses of war. The history of the statue's design explains why she wears a helmet rather than a liberty cap. The story of her casting reveals that some of the people who worked to create Freedom were not themselves free."

https ://www.aoc.gov/art/other-statues/statue-freedom