139 years ago today (today!), Andrew Hallidie tested the first cable car system near the top of Nob Hill at Clay and Jones Streets. The above picture was taken on the historic day. Muni drivers were so much better dressed in those days! Hallidie, the driving force behind the system got his inspiration on a wet, summer day in 1869. On that day, he witnessed a horse drawn streetcar slide under its own heavy load due to the steep slope and wet cobblestones. 5 (five!) horses died that day, and Hallidie was stunned into the inspiration for a safter alternative: The Cable Car.
Four years later, on August 2nd, the cable car had its first run on Clay and Jones. From Wikipedia:
Some accounts say that the first gripman hired by Hallidie looked down the steep hill from Jones and refused to operate the car, so Hallidie took the grip himself and ran the car down the hill and up again without any problems. The Clay Street line started regular service on September 1, 1873 and was a financial success. In addition, Hallidie's patents on the cable car design were stringently enforced on cable car promoters around the world, and made him a rich man.