* Time period: Walking to a one-room schoolhouse in a rural area in the 1800s would take a vastly different amount of time than taking a bus to a suburban school in the 1950s or driving to a school across town today.
* Location: Rural children often walked much farther than urban children. The distance varied dramatically depending on population density.
* Transportation: Before widespread automobile use, children walked, rode horses, or used other animal-drawn vehicles. The advent of school buses significantly reduced travel time for many.
* Family circumstances: Some children had longer commutes because they lived farther away from the school, had to help with chores before leaving for school, or walked siblings to school.
In short, the travel time to school for children has varied tremendously throughout history and across different geographic locations and socioeconomic groups. To give a more precise answer, you'd need to specify the time period, location, and other relevant factors.