Okay, kiddo! So a long time ago, in 1923, some adults in charge of running cities, like mayors and city councils, made a new law called the "municipal manager law." This law basically said that instead of having just one person in charge of the city (like a mayor), they would have a group of people that worked together called a "city manager."
The city manager's job was to help the city run better by making sure all the people who worked for the city (like police officers, firefighters, and other workers) were doing their jobs well and that things were getting done on time. The city manager would also work with the mayor and city council to make plans for the future of the city.
The idea behind the law was that having a group of people working together would be better than just one person trying to do everything on their own. It's like when you and your friends work on a project together, you can get more done and make a better plan than if you were just doing it by yourself.
The 1923 municipal manager law was important because it changed the way cities were run and helped make them more efficient and effective. Even today, many cities still use this idea of having a group of people working together to run things better.