The legal age of majority is the age at which a young person becomes an adult according to the law. This "magic age" does not seem particularly important for, let's say, a high school senior who is still living at home when he reaches this age; nevertheless, in the eyes of the law and accountability, everything has changed.
One who has reached the age of majority can be held legally accountable
It is the chronological moment when minors cease to legally be considered children and assume control over their persons, actions, and decisions, thereby terminating the legal control and legal responsibilities of their parents or guardian over and for them.
In most places, the age of majority is 18; however, this number varies by state. Five states in America have set the age of majority at 18 or graduation, whichever comes first. Another three states have determined that 19 is the age of majority, and one state, Mississippi, has set that age at 21. All the rest have settled on 18 as the appropriate age of majority (see the "contest" site attached below for a complete list of ages by state).
The age of majority may be the same or different than other age milestones, including the voting age, the drinking age, the driving age, or the age of sexual consent. We use the term "minor" for anyone who has not yet reached the age of majority.