"I am thirteen years old."

Thirteen Years was created in 1994.

The thirteen colonies. When we won the war, the colonies became the first thirteen states.

You have to be thirteen exactly thirteen years from your birth date for exactly one year. The year (or years, if you pass December) it is when are thirteen depends on the date of your birthday. I was born 11/01/1970 and was thirteen in 1983 and 1984.

The American Revolution was the war between the thirteen colonies and British mercantilism.