Critical Mass was started in 1992 in San Francisco, and was originally called the Commute Clot by the small group of people who participated in it. Those people handed out flyers to originally generate interest in the event, which clearly came from humble beginnings. While, of course, that changed that the events became popular throughout the globe, it is important to think back to just how small things started out for Critical Mass.
When you think of Critical Mass, you tend to think of a lot of people, because that's what a critical mass is. A critical mass by definition is an amount of people that will cause something to change, whether it is an amount of something that will cause a chain reaction, or the moment that something begins to take off in popularity, a critical mass is not achieved in most things by a small group of people. However, that is exactly what happened in the case of Critical Mass from a cycling perspective.
Critical Mass started out as a group of two dozen or so cyclists, who would hand out flyers on Market Street in an attempt to boost their membership. Eventually the strategies began to work, as evidenced by the massive popularity that Critical Mass has today, but it was certainly not an instant hit, as it took a while for the group in San Francisco to reach the critical mass that they needed to achieve the worldwide popularity that they now have.
Perhaps one of the most important things to happen in the history of Critical Mass is the decision for the organization to rename themselves Critical Mass. This happened after the relatively small group of cyclists watched a film about the culture surrounding motorists and cyclists in countries in Europe and Asia, where both sides had an understanding with one another that allowed them to communicate without any sort of signals. A term used in that movie to describe the threshold of motorists or cyclists required before one of the groups could move through an intersection was critical mass, so the group replaced the Commute Clot name with that, and it stuck from there.
It is hard to imagine a group with the name Commute Clot enjoying any sort of success, given the negative connotations associated with things like blood clots, so this was a great decision by the group, and one that led to a ton of success in the decades to come.