Agreed. Several States allowed women the right to vote before it became an Amendment: https://www.nps.gov/subjects/womenshistory/19th-amendment-by-state.htm
Several states and territories recognized women's suffrage rights before 1920, including Wyoming, Utah, Colorado, Idaho, Washington, California, Oregon, Montana, Arizona, Kansas, Alaska, Illinois, North Dakota, Indiana, Nebraska, Michigan, Arkansas, New York, South Dakota, and Oklahoma.
I think many associate states' rights with just segregation and ignore many of the positive aspects of federalism. States have been called "laboratories of democracy" because they can experiment with different policies which can be compared--term limits, public funding of elections and other policies have been compared for the various effects.
An interesting field of study is comparative state politics which examines the consequences of various methods of selecting judges, professional staff, term limits, etc.
[h=1] Politics in the American States: A Comparative Analysis 11th Edition [/h]
by Virginia H. Gray (Editor), Russell L. Hanson (Editor), Thad Kousser (Editor)