Related Clues:
- An earlier one may be recalled
- Paleozoic, for one
- Historical stage
- Ruth's was 2.28
- Unique stretch in time
- Paleozoic, for example
- --- of Good Feelings
- Several periods
- Period piece?
- Important historic period
- Geological time period
- Important time span
- Archeozoic, e.g.
- Depression, for one
- 1970's-80's cause, for short