Historical clue formulations

• 1873 invention first used in San Francisco — 2024-05-17
• Iconic San Francisco transport — 2023-03-21
• Symbol of San Francisco — 2021-03-06
• Symbol of San Francisco — 2019-06-08
• Conveyance in 67-Across — 2015-10-26
• Transportation on tracks — 2010-07-08
• Frisco transporter — 1995-07-27