How many pre-schools in the US?

There's no single, definitive answer to how many preschools are in the US. The data collection on this is fragmented and varies depending on the definition of "preschool" (e.g., including or excluding daycare centers with preschool programs, public vs. private, etc.). The National Center for Education Statistics (NCES) collects some data, but it doesn't provide a comprehensive count of all preschools. You'd likely find estimates varying significantly depending on the source.