Why? Because being able to write a good paper, memo, or argument will help you not only throughout law school but also throughout your legal career. Many attorneys report that the law school class that helped them the most when they began practicing law was their legal writing or research class.
Because legal writing and research are such valuable and necessary skills for practicing attorneys, the vast majority of law schools require students to take some kind of legal writing or legal research class their first year of law school. Thus, it is a good idea to consider getting a head start on it over the summer.