Data source: Alice M. Hetzel, U.S. Vital Statistics System Major Activities and Developments, 1950-95 (Hyattsville, Maryland: U.S. Dept. of Health and Human Services, Centers for Disease Control and Prevention, National Center for Health Statistics, 1997), 59 (PDF here).

The "death registration area" (DRA) and "birth registration area" (BRA) were/are the jurisdictions which meet the federal standard of registering at least 90% of each year's deaths (or births).

This is a little tool I'm using to work through some policy diffusion questions for my dissertation. It was built with Protovis. If you want to make something similar for your own research, you can browse the source code or download a copy from my GitHub repository.