First questions to consider:
- Can the data be found in the Federal Census?
- Was it available for each decade you are researching?
- Is the data available for towns less than 1,000 in population?
- If not, what do you do?
- Gather data from a larger geographic area?
- Contact local history centers to see what they may have
- Look for histories of the county (books), maps, atlases that might offer a clue