While any language will be useful for some jobs or for some regions, French is the only foreign language that can be useful throughout the world as well as in the United States. French as a foreign language is the second most frequently taught language in the world after English.
The International Organization of Francophonie has 51 member states and governments. Of these, 29 countries have French as an official language. French is the only language other than English spoken on five continents. French and English are the only two languages spoken worldwide.
When deciding on a foreign language for work or school, consider that French is a language that will give you many choices in your studies or your career.