The first was a necessary rule ... the Tenth Amendment also affirms the Constitution’s basic scheme of defining the relationship between the national and state governments.

In the Tenth Amendment, the Constitution also recognizes the powers ... Wyoming, which needed more women settlers, became the first state to grant women the right to vote in 1869.

First introduced in 1923, the Equal Rights Amendment has met the requirements for ratification. But its constitutionality is still an open question.