There are very few states in the U.S. with legal minimum ages for children home alone, but many state agencies have published guidelines. Illiniois, Maryland and Oregon are a few of the states with specific ages specified in their laws. 12 years of age appears to be the most common recommendation. http://www.latchkey-kids.com/latchkey-kids-age-limits.htm provides one guideline from a California agency representative who suggests that 8 year olds and over can be left at home for up to several hours (usually after school before a parent gets home from work). This site also provides a state by state comparison with references.