Related Clues:

• Graph line
• Tally
• Roaring Twenties, e.g.
• Sewer line?
• Time period
• Stretch of history
• Haw's companion
• Alter, in a way
• Part of B.C.E.
• The Thatcher years, e.g., in Britain
• Laundry detergent brand
• Historic time
• See 30-Across
• Stat for Clemens
• See 54-Down