Related Clues:

• Lengthy time unit
• A long long time
• It's going to be quite a while
• Elizabethan or Victorian
• Historical chapter
• Tom Seaver's 2.86, e.g.
• Swing __
• Just about forever
• Momentous time
• Stereo control
• Failed 27th Amendment
• It's full of periods
• American Depression, e.g.
• Many, many millennia
• Memorable period of time