Hi there. Personhood is a legal definition. Persons are endowed with the full range of rights of their civilizations. Fetuses are not persons, as has been demonstrated numerous times, from issues such as whether a fetus needs to pay half-price to ride a train (like a child does) to whether its mother has the right to invoke her own rights to determine her own medical care (or lack thereof) on its behalf.
I agree. Just considering the USA alone, women did not become fully persons before the law until 1919 while blacks did not become so until 1965.