I am interested in ascertaining how much continuity there is through time (e.g., from 19th to 20th century) for counties having the same name and FIPS number. One approach is to examine boundaries. Another approach is to see whether the county seat is retained. This is important since the population is likely to be concentrated around the county seat. If one is interested in continuity in population, therefore, this may be a better measure than spatial continuity. But how would one check this? Are there data sources that would list the country name, FIPS, and county seat?
Across different years, are counties with the same name and FIPS likely to contain the same county seat?