Historical clue formulations

• Word on a common bumper sticker — 2023-12-29
• Popular bumper sticker of the 2000s — 2021-12-30
• Get along — 2019-03-10
• Live in harmony — 2015-07-07
• Nice thing to do peacefully — 2011-02-04
• Get along peacefully — 1994-06-05