Question: San Francisco’s cable cars hold a distinction no other system on Earth can claim today. What is it?

Answer: They’re the world’s last manually operated cable car system. Andrew Hallidie opened the first line in 1873, inspired by the dangers horses faced pulling streetcars up San Francisco’s steep hills. More than 150 years later, a gripman still operates each car by hand, clamping onto a continuously moving cable beneath the street. The system was nearly replaced by buses in the late 1940s, but a citizen campaign led by Friedel Klussmann saved it. The cable car system was designated a National Historic Landmark in 1964.