How it fits together
After the Civil War, the 14th Amendment defined citizenship and promised equal protection. The 15th Amendment barred denial of voting rights on racial grounds. The 19th Amendment later prohibited denial on the basis of sex. These are different protections, added at different times.
A closer look
Amendments did not remove every barrier overnight. Discriminatory laws, violence, and administrative obstacles continued to exclude many voters. That distinction matters when the test uses broad wording such as “all men” or “all women”: the accepted date identifies a constitutional milestone, not instant universal access.