Although New York is generally a "progressive" State, it maintains some antiquated traditions, especially where its legal system is concerned.
A person can become an Attorney in New York State if:
(1) They attend an ABA-accredited law school for three years and pass the Bar Exam; or
(2) They remain "in residence" at a law school for at least 75 weeks as a full-time student or 135 weeks as a part-time student, and then pass the Bar Exam; or
(3) They attend the first year of law school and then "read law" at a New York law firm for three years---this is. work under the supervision of New York State-licensed Attorneys, and then pass the Bar Exam.
The first method is the most common, modern way; the other two methods hearken back to British colonial days, and are rarely used anymore. New York State's Bar Exam is considered one of the toughest in the nation.