Historical clue formulations

• Bird that's the U.S.'s national symbol — 2025-03-31
• Benjamin Franklin famously considered it "a rank coward" with "bad moral character" — 2022-01-23
• United States symbol — 2020-10-12
• American symbol — 2010-04-27
• Quarter back — 2009-07-05
• Symbol of 26-Across found on the 8-Across — 2008-10-06
• Quarter image — 2008-07-19
• Great Seal image — 2008-05-02
• Sacagawea flip side — 2002-12-10
• American symbol — 1995-03-05