I wasn't sure if this is in the right circle (women's history) because it is specifically about Black women's history in the US.

In African cultures, there were a large variety of styles–shaved, locs, knots, braids, partial shaves with shapes shaved into the hairline, etc... there were even styles that incorporated mud. I am unaware of what happened during the Arabic-African slave trade (which went on until quite recently), but suffice to say that Africans did not have any time or ability to care for their hair. In any case, Black hair has been seen as offensive and threatening for hundreds of years in what is known today as the United States. This has had a particular impact on women.

In 1763, the French colony of Louisiana was taken over by Spain. A free Black and mixed community had been established by that point, but their position in society was undefined. They were unenslaved, but still not granted the rights and freedoms of the white population.

The new Spanish government found the community threatening. In particular, they weren't thrilled with how attractive Black women were, or with how many white men were treating these women as legitimate partners. It was one thing to use a farm animal for sex (which we know is a thing in general with men) or even one of those lesser sub-humans, but this was different.

So the Spanish governor enacted the "Tignon Law." All free Black women had to wear a head covering like the one enslaved women wore to keep their hair protected while working. Part of the motivation behind this law was that these women's hair was considered one of their most attractive features.

In response, women complied with the law, but used colorful, expensive fabrics and tied them with ornate knots; they also decorated them with ornaments. Some of the tignons could be quite luxurious and costly.

In general today, Black women's natural hair is often seen as "unprofessional" and even "dirty." Technically this stigma affects men too, but most simply keep it short; women are more likely to want to keep their hair longer as a "feminine" trait and will face barriers to this in employment and society. There has been a strong stigma even within the Black community, and it's really only been in the last decade or two that more women have chosen to explore their natural hair textures.

African hair cannot be "left loose" unless it is very short. It must be styled in order to be well-maintained. Therefore, Black women who cannot wear natural styles have a choice--shave their hair, use chemical straightening treatments, or wear a wig. Protection for Black women's hair is still denied at the national level because it is still seen as offensive and dangerous enough that it should be hidden, removed, or chemically altered.

Chemical straightening treatments, in addition to being painful and dangerous (they can cause skin burns), also cause other health problems. They are linked to the higher preponderance of uterine fibroids that Black women have compared to the other women.

In 2019, the cosmetics corporation Dove, in partnership with senator Holly J. Mitchell and the CROWN Commission, introduced the CROWN Act. This act would mandate protection for Black children in grades k-12 as well as adults in the workplace in California who wear natural hair in various styles--locs, twists, braids, bantu knots, etc... I believe it passed there and has been adopted in 23 other states.

However, the bill was quashed at the federal level when it was introduced in 2022. It was the second time the bill was introduced, and senator Rand Paul filibustered successfully to get the bill killed. It has not been reintroduced since.